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RESEARCH IN THE SPACE SCIENCES 



A Bibliography of Research Performed 
Through the Space Sciences Laboratory, 
University of California, Berkeley 
with partial support from 
NASA Grant NGL 05-003-497 



Kinsey A. Anderson, Director 
and 
Principal Investigator 



Volume II, No. 1 
January - March, 19 75 



Space Sciences Laboratory, Series 16, Issue 26 



11 



TABLE OF CONTENTS 



K.A. Anderson and Group 

Impulsive (Flash) Phase of Solar Flares: Hard X-ray, Microwave, EUV and 
Optical Observations, S.R. Kane, in Coronal Disturbances , ed. by 
Gordon Newkirk, lAU, 105-141, 1974 

Acceleration of Electrons in Absence of Detectable Optical Flares Deduced 
from Type III Radio Bursts, Hc^ Activity and Soft X-ray Emission, 
S.R. Kane, R.W. Kreplin, M.-J. Martres, M. Pick and I. Soru-Escaut, 
Solar Phys., 38, 483-497, 1974 

Observed Correlations Between Interplanetary Magnetic Field Variations and 
the Dynamics of the Auroral Oval and the High-Latitude Ionosphere, 
C.P. Pike, C.-I. Meng, S.-I. Akasofu and J. A. Whalen, J. of Geophys. 
Res., 79, 5129-5142, 1974 

Hard Solar Flare X-ray Bursts on 8 December 1970, K.A. Anderson and W.A. 
Mahoney, Solar Phys., 35, 419-430, 1974 

Proton Fluxes Upstream from the Earth's Bow Shock, K.A. Anderson, R.P. Lin and 
C.-I. Meng, in Correlated Interplanetary and Magnetospheric Observations , 
ed. by D.E. Page, D. Reidel Publ. Co., 225-227, 1974 

Particles and Plasmas in the Earth's Magnetotail at 60 R^, L.M. Chase, R.P. 
Lin, R.E. McGuire and J.E. McCoy, in Correlated Interplanetary and 
Magnetospheric Observations , ed. by D.E. Page, D. Reidel Publ. Co., 
297-316, 1974 

Acceleration, Containment, and Emission of Very Low Energy Solar Flare 

Particles, R.P. Lin, R.E. McGuire and K.A. Anderson, in Coronal Disturbances , 
ed. by Gordon Newkirk, lAU, 461-469, 1974 

The Flash Phase of Solar Flares: Satellite Observations of Electrons, R.P. 
Lin, in Cotonal Disturbances , ed. by Gordon Newkirk, lAU, 201-223, 1974 

Mapping of Lunar Surface Remanent Magnetic Fields by Electron Scattering, 
R.P. Lin, R.E. McGuire, H.C. Howe, K.A. Anderson and J.E. McCoy, 1975 
(submitted) i 

Characteristics of the Magnetopause Energetic Electron Layer, C.-I. Meng 
and K.A. Anderson, 1975 (submitted) 

C.S. Bowyer and Group 

An Extreme Ultraviolet Search of the North Galactic Polar Region, P. Henry, 
R. Cruddace, F. Paresce, C.S. Bowyer and M. Lampton, Ap. J., 195, 107, 
1975 



ili 



C.S. Bov?yer and Group (Cont.) 

Soft X-ray Observations of Centaurus X-3 from Copernicus, B. Margon, K.O. 
Mason, F.J. Hawkins and P.W. Sanford, Ap. J. (Letters), 196 , L51, 1975 

A.L. Burlingame and Group 

Ketones Derived from the Oxidative Degradation of Green River Formation Oil 
Shale Kerogen, B.R.T. Simoneit and A.L. Burlingame, Advances in Organic 
Geochemistry, 1973, 6th International Congress of Organic Geochemistry 

The Maturation of Lunar Dust Grains, J.L. Bertaut, J. P. Bibring, J. Borg, 

A.L. Burlingame, Y. Langevin, M. Maurette, F.C. Walls, Lunar Science VI, 
The Lunar Science Institute, Houston 

Simulation of Lunar Carbon Chemistry: I. Solar Wind Contribution, J. P. Bibring, 
A.L. Burlingame, J. Chaumont, Y. Langevin, M. Maurette and P.C. Wszolek, 
Proceedings of the Fifth Lunar Conference, 2^, 1747-1762, 1974 

Study of the Organic Matter in the DSDP (Joides) Cores, Legs 10-15, B.R.T. 
Simoneit and A.L. Burlingame, Advances in Organic Geochemistry, 1973, 
6th International Congress of Organic Geochemistry 

Unimolecular Gas-Phase Hydrogen Randomization within 2-Methylpropane Radical 
Cations, P.J. Derrick, A.M. Falick and A.L. Burlingame, J. Chem. Soc, 
98-101, 1975 

M. Calvin and Group 

Kerogen Structures in Recently-Deposited Algal Mats at Laguna Mormona, Baja 
California: A Model System for the Determination of Kerogen Structures 
in Ancient Sediments, R.P. Philp and M. Calvin, 2nd Environmental Bio- 
Chemistry Conference, Burlington, Canada, 1975 

C.W. Churchman and Group 

The Costs of Efficiency, I.R. Hoos, JHE, XLVI , 2, 1975 

Author's Reply to Technology Transfer: Another Opinion, I.R. Hoos, J. Dynamic 
Systems, Measurement, and Control, 1975 



B. Fraenkel-Conrat 

The Specificity of Different Classes of Ethylating Agents toward Various Sites 
in RNA, B. Singer and H. Fraenkel-Conrat, Biochemistry, 14, 772, 1975 



IV 

/ 

B . Fraenkel- Conra t (Cont.) 

The Chemical Effects of Nucleic Acid Alkylation and their Relation to Muta- 
genesis and Carcinogenesis, B. Fraenkel-Conrat , Progress in Nucleic Acid 
Research and Molecular Biology, 15, 219-332, 1975 (reprint not available) 



H.H. Heckman and Group 

16 12 
Isotope Production Cross Sections from the Fragmentation of and C at 

Relativistic Energies, P.J. Lindstrom, D.E, Greiner, H.H. Heckman, 

B. Cork and F.S. Bieser, Phys. Rev. Lett., 1975 (in press) 

Momentum Distributions of Isotopes Produced by Fragmentation of Relativistic 
12c and ^^0 Projectiles, D.E. Greiner, P.J. Lindstrom, H.H. Heckman, 
B. Cork and F.S. Bieser, Phys. Rev. Lett., 1975 (in press) 

F.S. Mozer and Group 

Properties of the Wake of Small Langmuir Probes on Sounding Rockets, E.A. 
Bering, J. Atmos. and Terr. Phys., 37, 119-129, 1975 

The Temperature Gradient Drift Instability at the Equartorward Edge of the 

Ionospheric Plasma Trough, M.K. Hudson and M.C. Kelley, 1975 (submitted) 

Finite Heat Conduction Effects on Ion Cyclotron and Drift Cyclotron Modes, 
M.K. Hudsonr, 1975 (in press) 



P.B. Price and Group 

Composition and Energy Spectra of Hearvry Nuclei of TJnknovm Origin Detected on 
Skylab, J.H. Chan and P.B. Price, Phys. Rev. Lett., 1975 (submitted) 

Micrometeorites and Solar Flare Particles In and Out of the Ecliptic, I.D. 
Hutcheon, J. of Geophys. Res., 1975 (in press) 

Plutonium-224 Fission Tracks: An Alternative Explanation for Excess Tracks 
in Lunar Whitlockites , I.D. Hutcheon and P.B. Price, Science, 187 , 864, 
1975 

Slowly Braked, Rotating Neutron Stars, H. Sato, Astrophys. J., 195 , 743-749, 
1975 

Towards Diffraction-Limited Seeing of Dim Astronomical Objects from the 

Earth's Surface using Lidar, B.G. Cartwright and A.J. Gadgil, Astrophys. 
J., 1975 (submitted) 



V 



C.H. Townes and Group 

The Methanol Source in Orion at 1.2 Centimeters, M.F. Chui, A.C. Cheung, 
D. Matsakis, C.H. Townes and A.G. Cardiasmenos , Astrophys. J., 187 , 
L19^L21, 1974 

Molecule Searches in Comet Kahoutek (1973f) at Microwave Frequencies, 

S.A. Mango, K.J. Johnston, J.F. Chui, A.C. Cheung and D. Matsakis, 
Icarus, 23, 590-594, 1974 

Observations and Analysis of the Jovian Spectrum in the 10 Micron ^ Band 
of the NH , J.H. Lacy, A.I. Larrabee, E.R. Wollman, T.R. Geballe, 
C.H. Townes, J.D. Bregman and D.M. Rank, Ap. J. Lett., 1975 (submitted) 

Spectroscopy of the Orion Nebula from 80 to 135 Microns, D. Brandshaft, 
R.A. McLaren and M.W. Werner, Ap. J. Lett., 1975 (submitted) 



J.D. Young 

The Encephalitogenic Dose Response in Guinea Pigs of the Tryptophan Region 
of Myelin Basic Protein, J.D. Young, D. Tsuchiya, M. Geier, S. Geier, 
F.D. Westall, M. Thompson, R. Cyr, E. Ward and F. Yurochko, Immunological 
Communications, ^(3) , 219-226, 1974 

Experimental Allergic Encephalitis: Study of Cellular Immunity to the 

Enphalitogenic Determinant, L.E. Spitler, CM. von Muller, J.D. Young, 
Cellular Immunology, 15, 143-151, 1975 

The Encephalitogenic Dose Response in Guinea Pigs of the Tryptophan Region 
of Myelin Basic Protein, J.D. Young and F.C. Westall, South African 
Journal of Science, JO^, 252, 1974 

A Synthetic Peptide as a Substrate for Cyclic-Amp-Dependent Protein Kinase, 
P. Daile, P.R. Carnegie and J.D. Young, Proc. Aust. Biochem. Socl, 8_, 
1975 



THE FLASH PHASE OF SOLAR FLARES: 
SATELLITE OBSERVATIONS OF ELECTRONS 



R. P. LIN 

Space Sciences Laboratory , University of California, Berkeley, Calif. 94720, U.S.A. 



Abstract. Satellite observations of solar electrons bearing on flare particle acceleration and the generation 
af radio and X-ray emission are reviewed. The observations support a two stage acceleration process for 
electrons, one stage commonly occurring at the flare flash phase and accelerating electrons up to ~ 100 keV, 
and a second stage occurring only in large proton flares and accelerating electrons up to relativistic energies, 
t'he location of the acceleration region appears to be no lower than the lower corona. 

The accelerated non-relativistic electrons generate type III radio burst emission as they escape from the 
5un. Direct spacecraft observations of the type III emission generated near 1 AU and the energetic 
;lectrons, provide quantitative information on the characteristics of the electrons exciting type III 
:mission, the production of plasma waves, and the conversion from plasma waves to electromagnetic 
adiation. 
I 

1. Introduction 

[n the past decade spacecraft penetrating beyond the Earth's magnetosphere have 
seen able to directly observe the low energy particle emissions of the Sun. Low energy 
iolar particles are very frequently emitted from the Sun, especially non-relativistic 
ilectrons (see Table I) which commonly originate in small importance 1 flares or 
ubflares. Electrons up to ~10* eV in energy have been observed (Datlowe, 1971) 
rom larger flares. Energetic electrons appear to contain the bulk of the flare energy 



TABLE I 

Solar particle events in an active year 



Number of solar flares " ~ 1 6,000 

Number of non-relativistic electron events'" ~ 400 

Number of energetic proton events ^ ~ 70 

° Normalized for the whole Sun = number observed x 2. 

"' Normalized by cone of emission of ~ 70° for non-relativistic 

electron and ~ 100° for proton events. 



1 those flares where they are accelerated (Lin and Hudson, 1971; Syrotvatskii and 
Ihmeleva, 1972) and they are responsible for most of the observed flare energetic X-ray 
nd radio emission. The particle observations, combined with improved observations 
if solar electromagnetic radiation (much of which has also been provided by space- 
Iraft) define a detailed physical picture of energetic electrons in small solar flares, 
lere we review the results obtained from direct spacecraft sampling of electrons from 
ares pertaining to the acceleration of electrons at the sun and to the generation of 
/pe III radio emission at 1 AU. 



tirdon Newkirk. Jr. (ed.). Coronal Disturbances. 201-223. All Rights Reserved. 
Ipyright © 1974 by the lAU. 



202 



2. Interplanetary Propagation 



The electron observations at 1 AU are for the most part hmited to the particle intensity' 
above a given energy threshold. The intensity vs time profiles for flare associated 
events are generally consistent with an impulsive injection into the interplanetary 
medium. If the electrons are scattered a great deal in their propagation from the Sun 
to 1 AU (mean free path =i ^ 1 AU) then the intensity-time profile will look diffusive, 
as in Figure 1. If, on the other hand, very little scattering occurs (1^1 AU) then the 



^OPEN COUNTER (COUNT RATE x 10) 




IMP M 

DECEMBER 27, 1965 



-"'■'^-^'^''f^^v.^.vVtw^ 



l/^mAv'*'''"^'*''''*'''^^ 



UNIVERSAL TIME 



3 

O , 

O 10"' 



iMP-m 

25-26 JUNE 1966 



-OPEN COUNTER 
(COUNT RATE x IQ) 




^^fl^^^^,,^j^f,f,J,t,Jil4^^ 



I- I 



I I I I I I 



I I I I I I I I I L 



■25 



00 



26- 



-> 



UNIVERSAL TIME 



Fig. 1. Two diffusive electron events. The scatter counter is only sensitive to >45 keV electrons whik 

the open counter counts both >40 keV electrons and >0.5 MeV protons. The 27 December 1965 even' 

shows a rapid rise during onset which is observed for many electron events. 



intensity-time profile will consist of a rapid increase and decrease as in Figure 2. BotI 
kinds of events, diffusive and scatter-free (Lin, 1970), and events in between as well 
are observed, with scatter-free events (A> 1 AU) numbering ~20% of the total. 

It might seem, then, that it would be very difficult to derive the characteristics of th( 
injected electrons since the observations at 1 AU are greatly affected by the amoun 
of scattering and how it varies with energy, etc. Actually, however, the maximum flu: 
is remarkably insensitive to the details of the scattering (Lin, 1971), so long as there i 
enough scattering to give diffusive profiles. We can obtain the relationship betweei 
the maximum flux and the number of particles emitted for an event which can b 



=3 
O 
O 



THE FLASH PHASE OF SOLAR FLARES : SATELLITE OBSERVATIONS OF ELECTRONS 

10* 



203 



O 

J)J 1.04x10* 



a: 



-I N FLARE 
N26 W36 



•N FLARE 
N30 W33 




1600 



2000 2100 2200 



30 JULY 1967 (U.T.) 



ig. 2. Two scatter-free impulsive solar electron events from McMath plage 8905 (Wang et al., 1971). 

he sharp initial peak in the high energy channels place an upper limit on the duration of the electron in- 

ection into the interplanetary medium of S 3 min. Note the long decay following the initial peak in the 

low energy channels. 



dQ Id, 
dt fdr^ 



(1) 



iescribed by a diffusion equation (Parker, 1963) 

ivhere the diffusion coefficient D = Mr^, M and /? are parameters. Here g is the particle 
lensity at position r, time t, of energy E and a is the parameter specifying the dimension 
jf the space to be used. From Krimigis (1965), we obtain for an assumed isotropic 

luxJ=Qv/4n, ^ 



J(r, t) = 



■PY 



47t(2-/?)<2«+w<2-« r[a + l)/(2-)S)] \Mt 



1 



(0i+l)/(2-p) 



(2) 



204 R.P.LIN 

where N = number of particles emitted per unit solid angle, and v = particle velocity 
At time of maximum we obtain 



•'maxV ' ^max/ 

r a-f 



2-8 I V^ 



4;r(2-jS)<^"+^'«2-''» T [(a + 1)/(2 - ^)] V r 

Note that the relationship between N and J^^ is independent of M . Thus, as lonj 
as the diffusion coefficients for the different energy particles have the same spatia 
dependence (same P) regardless of the value of M, the constant of proportionalit} 
between J^^^ and Nv remains the same. In this case the shape of the flux spectrun 
derived from the maximum flux at each energy observed at 1 AU is exactly that of th( 
emitted particles. 

Some computations have been made of the validity of this method as X increase; 
(Lin et al, 1973b). These indicate that up to i;S0.3 AU this constant relationshij 
holds. 

3. Location of the Acceleration Region 

The electrons escaping to the interplanetary medium will lose energy during thei: 
passage through the solar atmosphere overlying the acceleration region. A straight 
forward calculation, assuming rectilinear upward path through fully ionized hydrogei 
to 1 AU without regard to deflections or other energy loss mechanisms (such as wav( 
particle interactions or radio emission), (Lin, 1973) shows that an initial power lav 
spectrum at height h at the Sun 

=A£f* with /I, (5 constants (4 

d£i 



becomes a peaked spectrum 



du AE2 



dE2 (El + 2kf*'^i^ 
with peak at 

andfe= — 2.6x 10~^* J^ ^^ n,(x) dx, whereniisincm"^, /lincm. 

In actuality the helical paths of the electrons along the field line and deflection 
will increase the path length traversed by the electrons in escaping to 1 AU, so that th 
£2™ given by Equation 6 will be a lower limit. A few low energy spectra of electron 
observed at 1 AU have become available from recent spacecraft observations (Fig 
ure 3). All of these spectra extend smoothly in a power law to below ~6 keV, and o: 
occasion to lower energies. Using Equation (6) we find that a peak <, 6 keV implie 



THE FLASH PHASE OF SOLAR FLARES: SATELLITE OBSERVATIONS OF ELECTRONS 



205 



that the total path length is given by 



lAU 



1 



n,(x)dx;S3.5xl0^^cm 



This corresponds to ;S60 /ig cm~^ of hydrogen, equivalent to an ambient density 
at the acceleration region of certainly less than ~ 10'° cm" ^. This density corresponds 
to a height of >2 x 10* km above the photosphere for a 10 X Baumbach-Allen active 
region density model. 

We wish to re-emphasize the fact that this estimater is a lower limit to the actual 



10' 



> 4 

« 10* 



10= 



X 

3 



10' 



z 
o 
(r. 



10 



~1 \ 

APOLLO 15 SUBSATELLITE 

I SEPTEMBER 1971 




10 10^ 10' 

ELECTRON ENERGY (keV) 



10' 






I 




1 iini[ ■T T iirnii i i 

APOLLO 16 SUBSATELLITE 
APRIL 27, 1972 


: 


= 


t 


\ 








1; 


E 




\ 








T 


" 






^ 


dE 


.5.10'E-' 


- 


r 






\ 






1; 


r 






\ 


V 




! 


r 








\ 


L, 


= 


r 












- 


r 










\ 


1 


- 












- 



I 10 10 10' 

ELECTRON ENERGY (KeV) 



Fig. 3. Two electron energy spectra extending to low energies. The I September event is accompanied by 
energetic protons while the 27 April event (from Lin et al., 1973) is not. Both spectra extend smoothly in 

a power law to below ~ 6 keV. 



height of acceleration since the effects which were not taken into account would tend 
to increase the minimum energy of the peak. Clearly electron acceleration must have 
occurred in the lower corona. Although only a few events have been observed to ener- 
gies below ~ 20 keV, in no events has a turnover been observed at higher energies. 
Thus electron acceleration at the flash phase appears to be a coronal phenomenon, 
at least for events observed to emit electrons into the interplanetary medium. 



206 R. P. LIN 

This location and ambient density is consistent with the observed starting frequen- 
cies (~ 200-1000 MHz) of type III bursts, and is also consistent with the occasional 
observation of an electron event at 1 AU without detectable X-ray emission (Kane 
and Lin, 1972). Presumably in those events the magnetic field structure in the vicinity 
of the acceleration region is such as to prevent the electrons from entering dense re- 
gions where a detectable X-ray flux would be produced. 

4. Accelerated vs Escaping Electron Energy Spectra 

Non-thermal X-rays give direct information on the electrons at the Sun. The X-ray 
spectrum can be directly related to the instantaneous X-ray producing electron 
spectrum (Brown, 1971 ; Kane and Anderson, 1970). This relationship can be written 
for a power law X-ray spectrum as 

dn AE~'''^^'^ 

— = 3.85x10^1 y(y-l)^B(y-i I) ^cm-^keVS (7) 

dE rii V 

where 

B{x, y) is the beta function, n, the ambient ion density, V the volume of the X-ray 
region, and A, y constants. 

The relationship of the instantaneous X-ray producing electron spectrom to the 
accelerated electron spectrum depends on the evolution of the electrons subsequent to 
acceleration. Suppose the electrons are accelerated in one region and produce the bulk 
of the observed X-rays in another region (these two regions may be one and the same 
but for the sake of generality we will allow them to be different). The evolution of the 
electron distribution, N(E, f)=F(dn/d£), where V= volume in the X-ray emitting 
region, can be described by the equation 



dN{E,t) , , N{E,i) d V , d£" 



(8) 



where F{E, t) is the input source of electrons keV" ' s" S N(£, t)/Te(£) is the numbei 
of electrons escaping the region s" ' keV" \ and the third term describes energy loss 
processes for the electrons. Note that X-ray observations define N{E, t) subject to s 
choice of ambient density M; (Equation (7)). Thus this equation can be solved foi 
F{E, t), given n^ and given the form of Te(£) if only coUisional energy losses are assumec 
to be important. 

To a good approximation we can consider iV(£, t) as constant over some tim< 
interval. At, and zero outside that interval. This removes the time dependence of the 
equation. Additionally we shall consider only the power law case, N{E, t) = BE'^, sc 



THE FLASH PHASE OF SOLAR FLARES : SATELLITE OBSERVATIONS OF ELECTRONS 



207 



that inserting for dE/dt the energy loss in ionized hydrogen (Trubnikov, 1965) 

d£ 

_= -4.9 X 10-^ n;£-i/2(keV s'^), 

dt 

where «— ambient density in cm"^ and E is in keV, Equation (8) becomes 

4.9 X 10"' 



/rrp^ AffA 1 , 4.9xlO-^M^+i) -| 



(9) 



(10) 



We have computed the anticipated energy dependence of F{E, t) compared to 
N{E, t) and dJ(hv)/d{hv), and the energy dependence of the escaping electrons for 
two extremes: 

(1) where the escape term is much larger than the collisional energy loss term. This 
situation is the thin-target approximation for X-ray emission. 

(2) where the collisional energy loss term is much larger than the escape term. This 
situation is the thick-target approximation for X-ray emission. 

We have used two obvious choices for the energy dependence of x^, although other 
forms might be appropriate. These two are: (1) Te=constant, and (2) z^ccl/E^''^, i.e., 
proportional to the scale size of the X-ray region divided by the particle velocity. The 
results are summarized in Table II. 

TABLE II 

Spectral dependence of electrons and X-rays 



Thick target 



Thin target 



Spectrum of X-rays 
Spectrum of electrons in X-ray 
emittmg region 7V(£')oc-—oc£' " 

QlE 

Spectrum of accelerated electrons 
/•(£')oc£-''- 

I Spectrum of electrons escaping from 
the X-ray region, S(E)ccE''- 



<U{hv) 



dJ(/iv) 



d(Av) ' 


*V'" 


1 






d{hv) "'"' 


5 = y-i 










5 = y-i 


Sa = l+^ 










i5„ = y — i for T^ = constant 
5, = 7-lforT,oc£-"^ 


'5e=y-i 


for 


T^e 


= constant 


r. „ y-j for te = constant 


5^=y-\ for 


■^e 


oc£- 


1/2 



The spectrum of electrons escaping from the X-ray region is not necessarily the 
spectrum of the electrons escaping to the interplanetary medium. The electrons need 
not escape to the interplanetary medium to be lost from the X-ray region; they may 
also escape to the low density, n, < 10^ cm" ^, upper corona, where the flux of X-rays 
they produce will be below the threshold of current X-ray detectors. Also the ac- 
celeration region may be much higher in the solar atmosphere than the X-ray region, 
and the electrons observed in space may have come directly from the accelerated 
population (i.e., S^ = S„). 

Datlowe and Lin (1973) noted that it is possible to distinguish between thick and 
thin target cases under the assumption that the spectrum of electrons observed in the 



208 R.P.LIN 

interplanetary medium is representative of the accelerated electron spectrum (i.e., 
^e=6^, see Table II). For a flare event where high energy resolution measurements 
were available for the electrons and X-rays above 20 keV (see Figure 4), the result 
was ^a = 7 — i, favoring thin target. Other X-ray electron events studied where only 
measurements with poor energy resolution were available are also generally consistent 



10 



— I — I I |iiii| 

UCSD-OSO-7 

SOLAR X-RAY INSTRUMENT 
FEBRUARY 26, 1972 

i8;04;58-i8;i3;5i 



> 



o 
a> 

.^ lo' 



10^ 



o 
a. 



10" 



10 




10 



6.5(E/I0 



lii.il 



50 100 

Photon Energy 
KeV 



10 r 



> 

a> 
:^ 

L 10' 
o> 

in 

• 

u 
a> 
(/) 

• 
OJ 

e 

^10° 
UJ 

T3 



T — r 



ELECTRONS 

I I I I III 1 — r I I I 1 1 



10 



10' 




IMP -6 
26 FEBRUARY 1972 
1910 UT 



I I ' MM 



10'' 



ENERGY ( KeV ) 



Fig. 4. The spectra of hard X-rays and electrons observed at 1 AU for the same flare event. The photons 
fit a power law spectrum dJ{hv)/d{hv) = A {hv)~ ^ where 7 = 4.0 + 0.3, while the electrons fit a spectrum 
dy/d£'=6.75 X 10^ £"^'. Since d«/d£'=!; dJjAE where v is the electron velocity, the electron fit a density 
spectrum dn/dEccE~' with 5 = 3.6 ±0.1. These two spectra are consistent with thin target emission under 
the assumption the escaping electrons have the same spectrum as the accelerated electrons. 



(see Lin and Hudson, 1971 ; Kane and Lin, 1972) with a thin target model. The thin tar- 
get case is also consistent with the location of the acceleration region (m; < 10^° cm" ^) 
derived from considerations of the low energy electron spectrum observed at 1 AU. 
In favor of thick target processes we note that if non-relativistic electrons penetrate 
to the dense (n;>10^^ cm"^) regions of the chromosphere-corona boundary and 
below, they could produce the observed EUV and perhaps provide the energy for 
heating the Ha flare region through coUisional loss (and possibly even heat the white 
light flare region) (Hudson, 1972). The close time coincidence between the hard X-ray 
spike and the EUV spike (Kane and Donnelly, 1971) is consistent with such an inter- 
pretation. At those densities the thick-target approximation would certainly be 
appropriate. 



THE FLASH PHASE OF SOLAR FLARES I SATELLITE OBSERVATIONS OF ELECTRONS 209 

There are several possible ways of reconciling the observations in support of thick 
and thin target. One possibility is that the electrons injected into the interplanetary 
medium may have a spectrum modified from that of the electrons initially accelerated. 
From comparisons of the total energy in accelerated electrons derived from the X-ray 
observations and the total energy in escaping electrons, Lin and Hudson (1971) found 
that the escape efficiency is only ~0.1 to 1%. Thus the probability of escape of the 
electrons into the interplanetary medium may be a function of electron energy. We 
do not favor this possibility in view of (a) the relatively small amounts of matter 
which are traversed by the escaping electrons, and (b) the otherwise coincidental 
agreement between the X-ray and electron spectra. 

A second possibility is that electrons of low energies, say below ~ 10 keV, are 
described by the thick target approximation while higher energy electrons are in an 
essentially thin target situation (Kane, 1973). This dichotomy could arise, for example, 
if the electrons are accelerated and contained by a magnetic 'bottle' in a low density, 
n, ;S 10^ " cm ~ ^, region. Electrons only appear in high density, M; ^ 10^ " cm " ^, regions 
near the feet of the magnetic bottle if they are scattered into the loss cone. Since the 
amount of scattering is a strongly decreasing function of energy, essentially only the 
low energy electrons will be dumped into the loss cone. This interpretation is con- 
sistent with the observations which show that the correspondence between rising 
portion of the EUV emission and the rising portion of the non-thermal X-rays is best 
for the lowest energy, ~ 10 keV, X-rays. 

A third possibility is that the acceleration of the escaping electrons is separate from 
the acceleration of the electron producing X-rays. However the time of injection of 
the electrons into the interplanetary medium, which can be obtained accurately 
(<, 10 min) by analyses of the velocity dispersion observed during the onset of electron 
events at 1 AU, is clearly between the Ha onset and maximum, i.e., at the time of the 
flash phase X-ray and radio flare phenomena. The duration of the injection is in- 
ferred to be ;S3 min from the duration of the highly scatter-free events. Furthermore, 
escaping electrons generate type III emission. Type III emission occurs exactly at 
the time of X-ray bursts to within seconds when both are observed from flares (Kane, 
1972). 

These considerations indicate that the >20 keV electron spectrum observed at 
1 AU is probably an essentially undistorted sample of the electrons accelerated in the 
flare. 

5. Two Stage Acceleration 

Two types of electron spectra are observed (Lin, 1970). For events which are un- 
accompanied by energetic protons * and relativistic electrons, i.e., pure non-relativistic 
electron events, the electron spectrum can be fit to a power law with exponent from 
~ 2 to 5, usually with a steepening to > 5 at ~ 100-200 keV (Figure 5). Events which 
are accompanied by energetic protons usually have electron spectra which extend 

* Above a threshold of ~0.3 (cm^ s ster)"' above 10 MeV. 



210 R.P.LIN 

smoothly in a power law to relativistic energies (Figure 6). These two types of spectra, 
one with a 'cut-off and one without, suggest two stages of acceleration, one a flash 
phase acceleration of mainly just ~ 5-100 keV electrons, and the second an accelera- 
tion of protons and electrons to high, even relativistic energies which occurs only in 
some flares. This concept is further supported by spacecraft observations which in- 



I0« 



I I \ Miiij — i—r 

IMP-4 JULY 30, 1967 



^l I I lMll| — I I I nil 




KINETIC ENERGY (KeV) 



> 
UJ 



10' 



10 



E FT 



o 

u 

(O 



3 



10 



10' 



rrm]- 



I I I IIT 



IMP-6 
MARCH 21,1971 



.A ^ 



II I I I III 



10 








10 



ENERGY (KeV) 



Fig. 5. The electron energy spectra of the events of Figure 2 (from Wang et al., 1971) illustrating the 

steepening in the spectrum above ~ 100-200 keV typical of pure electron events. Note the wide variation 

in flux from the 30 July 1967 events to the 21 March 1971 event. 



dicate that relativistic electrons and energetic protons are usually injected into the 
interplanetary medium >10 min after the non-relativistic electrons (Figure 7) 
(SuUivan, 1974; Simnett, 1974; Lin and Anderson, 1967). 

Two stages are sometimes observed in the hard X-ray event accompanying energetic 
proton flares (Figure 8) (Frost and Dennis, 1971). The X-ray energy spectrum shows 
a cut-off at ~ 100 keV for the flash phase but no energy cut-off even to the limits of 
their observation ( > 250 keV) in the long second phase. That phase starts at the onset 
of the type II burst. The radio. X-ray, and particle observations are generally consistent 
with the acceleration of particles in the second state by the type II shock front in the 
corona by a stochastic Fermi-type mechanism. The X-ray event of 30 March 1969 
(Figure 8) was associated with a behind-the-limb flare ( ~ W 1 10°) so the origin of the 
X-ray burst must be in the corona. Interplanetary shocks and the Earth's bow shock 
both accelerate particles, electrons and nuclei, up to energies of ~ 10^ keV (Fan et al, 
1964; Anderson, 1965 ; McGuire et al, 1972) and ~ 10 MeV (Palmeira et al, 1971) re- 



THE FLASH PHASE OF SOLAR FLARES: SATELLITE OBSERVATIONS OF ELECTRONS 



211 



10 F 





10- 






> 




0) 




2 


£ 


^ 


10 


a> 








v> 




o 






10 



cvj 

£ 

O 2 

-- 10 
X 

_l 

^10 



o 

\- 

o 
llJ 



iiiii| I iiiiiii| I iiiiiiii I HUM 

IMP-4 
MAY 28. 1967 

A u Cal 
■.o u Chicago 
• GSFC 



UJ 



10' - 



10' 




iim 



10^ 



ELECTRON ENERGY (MeV) 



Fig. 6. The differential electron energy spectrum for the mixed electronproton event of 28 May 1967, 
compiled from four different detector systems aboard IMP-4. The lowest energy point is obtained from 
Geiger Miiller detector observations (Lin, 1970). The University of Chicago points are from solid-state 
detector telescopes (Sullivan, 1973), and the points above ~2 MeV are from the Goddard Space Flight 
Center range and energy loss scintillation detectors (Simnett, 1971). The points fit to a single power over 
three decades in energy, even though they are from several different detectors with different view directions. 

spectively. In the much higher magnetic fields and densities near the Sun it seems 
likely that substantially higher particle energies will be attained. 



6. Generation of Type III Radio Emission 

It is well established that energetic electrons generate most (if not all) of the non- 



212 R.P.LIN 

thermal radio emission observed from the Sun. Detailed calculations of gyro-synchro- 
tron and synchrotron emission of energetic electrons in solar magnetic fields give 
generally good agreement with observations of impulsive microwave bursts and 
type IV emission. However until recently the various theoretical treatment of type III 
emission differed as to the exciter, whether electrons or protons or waves, and numbers 



I03 



T3 

C 

o 
o 



(f) 



10 



3 
O 

u 



The University of Chicago 

IMP- 4 

3 June 1967 




0.17- 1.0 MeV 




0600 0700 0800 

UNIVERSAL TIME 



0900 



Fig. 7. The delay of the relativistic (0.75-1 .6 MeV) electrons vs the non-relativistic electrons (0. 1 7-1 MeV) 

is illustrated here. The onset of the soft 2-12 A flare X-rays is denoted by (a), the 0.17-1.0 MeV electron 

onset by (b), the 0.75-1.6 MeV onset by (c), and the 9.6-18 MeV proton onset by (d) 

(taken from Sullivan, 1973). 



of particles needed varied over 10-12 orders of magnitude (Evans et al, 1971), Thus 
direct observations of the exciter, and simultaneously the type III emission generated 
by them at 1 AU, are of critical importance in establishing a firm theoretical base for 
the emission processs. 



THE FLASH PHASE OF SOLAR FLARES : SATELLITE OBSERVATIONS OF ELECTRONS 



213 



/iVV»V»r 




lO^'l 1 — I I I I lll| 



10' 



10' 



10- 



o 

X 



10- 



10- 



10- 




20 



' 



-Lt 



MM n i l r 




I I Mill 



I 



40 60 100 200 300 20 40 60 100 200300 

ENERGY (KeV) 
Fig. 8. The two-stage hard X-ray burst of 30 March 1969 (from Frost and Dennis, 1971), which was fol- 
lowed by an intense mixed electron-proton event observed at 1 AU. This X-ray event presents clear evi- 
dence for two-stage acceleration. Photon energy spectra during the initial X-ray burst (shown in the middle 
panel marked 'a') have a spectrum steepening above ~ 100 keV, fairly typical of flash phase events. The 
spectra during the second phase (shovm in the right panel marked 'b') which starts at the time of intense 
type II emission (Smerd, 1970) shows a smooth and very hard spectrum to the upper limits of the X-ray 

detector's energy range (~ 300 keV). 

6.1. Physical mechanism 

Type III solar radio bursts are the most common type of impulsive phenomena 
observed from the Sun. These bursts are characterized by a rapid frequency drift from 
high to low frequencies, and occasionally by the presence of two bands of emission, 
one at approximately twice the frequency of the other (see reviews by Wild, et al, 
1963 ; Wild and Smerd, 1972). A theoretical basis for the plasma hypothesis for type 
III solar radio bursts (Wild, 1950) was first introduced by Ginzburg and Zheleznyakov 
(1958), and although it has been developed and refined in the intervening years, the 
basic ideas have remained unchanged (see review by Smith, 1973). A group of fast 
particles injected near the Sun generate longitudinal electron plasma waves at 
frequencies near the local plasma frequency as they pass through the coronal plasma. 
These plasma waves then scatter off ion density fluctuations to produce electro- 
magnetic radiation near the plasma frequency (fundamental), and off other plasma 
waves to produce emission at twice the plasma frequency (2nd harmonic). As the 
fast particles go upward in the corona and into the interplanetary medium the radio 
emission will drift from high to low frequencies. Typical drift rates for these bursts 
indicate velocities of ~ 0.3-0.5 c for the particles where c is the speed of light. 

The plasma waves are generated through a coherent Cerenkov plasma process. In 
order to produce plasma waves more rapidly than they are damped, the velocity 
distribution of the fast particles must have a positive slope, that is, a peak must exist 



214 R.P.LIN 

in the non-thermal particle velocity distribution. Observations of the characteristics 
of type III bursts and the particles that excite them will thus provide a test of basic 
beamplasma and mode-mode coupling theory over a wide range of plasma con- 
ditions. 

6.2. THE TYPE III BURST EXCITER 

Wild et al. (1954) were first to suggest that energetic protons might be the exciters of 
type III emission. More recently Smith (1970) summarized the theoretical difficulties 
of stabilizing a spatially unbounded and homogeneous electron stream, and noted 
that a proton stream can be stabilized. Smith (1970) suggested that the ~20-100 MeV 
protons which might produce the burst at the Sun were so few in number that after 
diffusion in the interplanetary medium their fluxes would be too low to observe at 
1 AU. However, the observations of type III bursts generated near 1 AU imply that 
substantial fluxes of protons sufficient to produce emission should be observed at 
] AU. Such fluxes are not generally observed except in large proton events which 
are quite rare compared to electron events. 

The theoretical difficulties for electron streams can apparently be overcome by 
considering a spatially bounded stream with inhomogenities in the front and back 
(Zaitsev et al, 1972). In addition direct observations of the electron velocity distribu- 
tions at 1 AU show that peaked distributions do exist, contrary to the theoretical 
predictions otherwise. 

A very highly significant correlation, almost one to one, exists between intense 
kilometric wavelength type Ill's and >20keV electrons observed at 1 AU from 
flares located in the western solar hemisphere (Alvarez et al., 1972). In addition storms 
of weak type III bursts are observed at hectometric wavelengths which appear to be 
closely related to type I storms at metric wavelengths (Fainberg and Stone, 1970). 
These type III storms are accompanied by non-impulsive co-rotating > 20 keV elec- 
tron fluxes observed at 1 AU. 

Recently Frank and Gurnett (1972) and Lin et al. (1973a) have reported observa- 
tions at 1 AU of energetic electrons and type III burst emission at the low frequencies 
characteristic of the near 1 AU plasma environment. Frank and Gurnett (Figure 9) 
did not observe radio emission simultaneously with the arrival of the 5-6 keV elec- 
trons, which, in their interpretation, are the exciters of the emission. Rather they as- 
sumed that the radiation is generated primarily at the fundamental, i.e., local plasma 
frequency, and that the lowest frequency radiation they observe, ~31 kHz, originates 
some distance away from 1 AU. Approximately 2600 s after the onset of the 31 kHz 
emission the ~ 6 keV electrons are observed to arrive. Although the fundamental 
emission generated at 1 AU (~20 kHz) is not observed, the authors note that the 
calculated time of onset of the fundamental emission is in agreement with the arrival 
of the ~6 keV electrons (i;«0.15 c). Since the drift rates of bursts near the Sun in- 
dicate velocities of ~0.3 c, they conclude that deceleration of the electrons may be 
substantial. 

Lin et al. (1973a) located the position of the type III burst emission at each fre- 



THE FLASH PHASE OF SOLAR FLARES : SATELLITE OBSERVATIONS OF ELECTRONS 



215 




0600 0700 OeOO 0900 1000 1100 1200 1300 1400 150O 1600 1700 1800 UT 



Fig. 9. Simultaneous electron and type III burst observations at 1 AU (from Frank and Gurnett, 1972). 
The local electron plasma frequency is ~ 20 kHz, but no oscillations were observed at that frequency. If 
the radio emission is at the fundamental of the plasma frequency then the 5.5-6.3 keV electrons would 
be likely candidates for the burst exciter. If, on the other hand, the radio emission is at the second har- 
monic of the plasma frequency then higher energy, £ 10 keV, electrons would coincide with the emission 

(see text). 



216 R.P.LIN 

quency (Figure 10) from the spin modulation of the radio signal. The emission origi- 
nating at 1 AU was then compared with the particle data. Their results show (Figure 
11) that the onset of the emission located at 1 AU corresponds to the arrival of elec- 
trons of ~ 100 keV energy. The subsequent build up of the radiation corresponds to 
the arrival of lower energy electrons, until maximum is reached when ~10keV 




45 keV Electrons 



SOLAR 
RADII |oo4. 



UNIVERSAL TIME 




MAY 16,1971 
1233 -IZSS UT 



Fig. 10. (a) The May 16, 1971 event. The upper two channels are sensitive to low energy protons as well 
as electrons while the lower channel is sensitive only to electrons. Some upstream terrestrial protons are 
observed ~ 1430-1500 UT, a time well after the period of analysis, (b) The trajectory in the interplanetary 
medium of the type III burst of 16 May 1971, determined from the spin modulation of the observed radio 

signal at different frequencies. 



electrons first arrive. By the time 6 keV electrons arrive the emission is already de- 
caying rapidly. 

Since the propagation of these electrons may differ markedly from event to event, 
depending on the changeable scattering characteristics of the interplanetary medium, 
two events were compared. One event was scatter-free, the other diffusive. The fre- 
quency drift rate of the interplanetary type III bursts was more rapid for the scatter- 
free event and less rapid for the diffusive event, corresponding nicely to the difference 
in the computed distance traveled for the first arriving electrons of 1.4 AU in the 
scatter-free event and 1.7 AU for the diffusive event. 

The evidence from radio studies indicate that the second harmonic emission rather 
than fundamental is predominant for low frequency type III radiation (Fainberg et al, 
1972; Smith, 1972; Malitson et al, 1973; Haddock and Alvarez, 1973). Thus, the 
frequencies of the near 1 AU radiation are ~ twice the local plasma frequency. Under 
the assumption of second harmonic radiation the observations of Frank and Gurnett 
would be in close agreement with Lin et al. (1973a). 

Even under the second harmonic hypothesis some apparent deceleration is ob- 
served (Fainberg et al, 1972). This can be attributed to scattering of the electrons as 
they propagate outward in the interplanetary medium. Such scattering will lower the 
apparent velocity along a smooth spiral field line. 



THE FLASH PHASE OF SOLAR FLARES : SATELLITE OBSERVATIONS OF ELECTRONS 



217 



5 i t 

—I V) 



\ 



- in Qj 






(»HX)A3N3n03aj 



o 
o 

<0 



82 



1X1 



< 



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ac o 


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li^ C 


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^ 


H-S 





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S 2 








sp; 




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c < 












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S " 




Jo » 




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>i 








5: " 


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S=^ 


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^ EC 




O 


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g=i 





CHX) A0N3nO3ad 



j3 



60 



218 



R. P. LIN 



6.3. Comparison with theories 

Using calculated incoherent Cerenkov emission efficiency (Cohen, 1958) and a maxi- 
mum estimated value for the efficiency of coupling to EM radiation, we find that the 
emission from incoherent Cerenkov processes calculated for the observed electron 
fluxes is insufficient to account for the observed emission. 

The peaked distribution needed to generate coherent Cerenkov radiation is clearly 
present in the electrons (Figure 12). This peaked distribution arises from velocity 



o 




100 20 

ENERGY (k«V) 
IMP-6 SOLAR ELECTRON EVENT, MAY 16, 1971 

Fig. 12. The energy spectrum of the electrons in the 16 May 1971 event at different times during the onset. 

dispersion rather than an initially peaked distribution of injected electrons at the 
Sun, since the injection spectrum at the Sun is observed to extend down to ;g 5 keV 
without a peak. 

The radio emission is observed to increase in intensity until the peak in the electron 
distribution falls below ~15keV. The radio burst begins a constant exponential 
decay, independent of the behavior of the electron flux, after the peak in the electron 
distribution goes below ~ 10 keV. 

It should be noted that the coherent Celenkov processes, at least in these observa 
tions, are not so strong as to substantially modify the peaked distribution. That dis- 
tribution evolves essentially as would be anticipated from velocity dispersion alone. 
The implication is that the time scale for relaxation of the beam through the wave- 
particle interaction is long compared to the time scale for evolution of the distribu- 
tion by velocity dispersion. This is contrary to the expectation of most theories for 
type III emission. 

One factor not considered in most theoretical treatments which may be relevant 
in explaining the long time scale for relaxation is the angular distribution of the elec 
trons. The average distribution for the 16 May 1971 event during the period of genera 
tion of type III emission is shown in Figure 13. The distribution is not just outward 



THE FLASH PHASE OF SOLAR FLARES: SATELLITE OBSERVATIONS OF ELECTRONS 



219 



along the field line as assumed by most theoretical models, but instead is relatively 
isotropic, with a maximum to minimum ratio of ~2:1. This angular distribution 
presumably arises from the pitch-angle scattering of the electrons by irregularities in 
the interplanetary magnetic field. 
Table III lists some characteristics of the low frequency type III burst at 1 AU 



IMP-6 
MAY 16, 1971 
1305- 1345 UT 




Fig. 13. The pitch angle distribution of the >45 keV electrons during the onset of the 16 May 1971 event. 
The approximate direction of B is indicated by the arrow. 



TABLE III 

Relevant parameters of type III bursts and burst exciters at 1 AU 



(1) Type III burst 

(a) Typical frequencies of observation (2nd harmonic) 

(b) Intensity of emission 

(c) Cross-sectional area of source 

(d) Average emissivity of source 

(2) Fast electron exciters 

(a) Typical energy of electrons 

(b) Density of fast electron at burst maximum 

(c) Total number of fast electrons producing emission 

(d) Average rate of energy loss to electromagnetic 
emission (per electron) 

(e) Average interparticle distance 

(3) Ambient plasma medium (solar wind) 

(a) Mean densities 

(b) Mean temperatures - electron 

- proton 

(c) Debye length 



~ 40-60 kHz 
~3xlO-^'' 
Wm-^Hz 
~ 10" cm^ 
-6x10"^* 



erg cm ^ s ' 



~ 10-100 keV 
~10-*cm-' 
-10" 
~4xlO-'keVs-' 

~10^cm 



5-10 cm-' 
~1.2xI0'K 
~7xlO*K 
~10='cm 



220 R.P.LIN 

and some parameters of the emission process. It is clear from these preliminary 
studies that a quantitative plasma theory for type III bursts can be obtained through 
further observations of this kind. Such observations and theory, besides illuminating 
problems of plasma physics otherwise impossible to study, will also be applicable for 
the quantitative interpretation not only of solar flare radio phenomena, but possibly 
of galactic and extragalactic radio emission as well. 

Acknowledgements 

I wish to acknowledge discussions with Drs S. R. Kane and K. A. Anderson. This 
research was funded in part by NASA grant NGL-05-003-017. 

References 

Alvarez, H., Haddock, F., and Lin, R. P. : 1972, Solar Phys. 26, 468. 

Anderson, K. A.: 1965, Proc. 9th International Conf. on Cosmic Rays, London, p. 520. 

Brown, J. C: 1971, Solar Phys. 18, 450. 

Cohen, M. H.: 1958, Phys. Rev. 123, 711. 

Datlow, D. : 1971, Solar Phys. 17, 436. 

Datlowe, D. and Lin, R. P. : 1973, Solar Phys. 32, 459. 

Evans, L. G., Fainberg, J., and Stone, R. G.: 1971, Solar Phys. 21, 1968. 

Fainberg, J., Evans, L. G., and Stone, R. G. : 1972, Science 178, 743. 

Fainberg, J. and Stone, R. G.: 1971, Astrophys. J. 164, L123. 

Fan, C. Y., Gloeckler, G., and Simpson, J. A. ; 1964, Phys. Rev. Letters 13, 149. 

Frank, L. A. and Gurnett, D. A.: 1972, Solar Phys. 27, 446. 

Frost, K. J. and Dennis, B. R. ; 1971, Astrophys. J. 165, 655. 

Ginzburg, V. L. and Zheleznyakov, V. V.: 1958, Soviet Astron. AJ2, 653. 

Haddock, F. T. and Alvarez, H. : 1973, Solar Phys. 29, 183. 

Hudson, H. S.: 1972, Solar Phys. 24, 414. 

Kane, S. R.; 1972, Solar Phys. 27, 174. 

Kane, S. R.: 1973, Bull. Am. Astron. Soc. 5, 274. 

Kane, S. R. and Anderson, K. A.: 1970, Astrophys. J. 162, 1003. 

Kane, S. R. and Donnelly, R. F.; 1971, Astrophys. 7. 164, 151. 

Kane, S. R. and Lin, R. P. : 1972, Solar Phys. 23, 457. 

Krimigis, S. M.: 1965, J. Geophys. Res. 70, 2943. 

Lin, R. P.; 1970a, J. Geophys. Res. 75, 2583. 

Lin, R. P.: 1970b, Solar Phys. 12, 209. 

Lin, R. P. : 1971, Conf. Papers, 12th International Conf. on Cosmic Rays, Hobart, Tasmania, Australia, 5 

1805. 
Lin, R. P.: 1973, in R. Ramaty and R. G. Stone (eds.), Proc. Symposium on High Energy Phenomena ot 

the Sun, Goddard Space Flight Center, Greenbelt, Maryland, September 1972, p. 439. 
Lin, R. P. and Anderson, K. A. : 1967, Solar Phys. 1, 446. 
Lin. R. P. and Hudson, H. S.; 1971, Solar Phys. 17, 412. 
Lin, R. P., Evans, L. G., and Fainberg, J. : 1973a, Astrophys. Letters 14, 191. 
Lin, R. P., Wang, J. R., and Fisk, L. A.: 1974, /. Geophys. Res., in preparation. 
Malitson, H. H., Fainberg, J., and Stone, R. G.: 1973, Astrophys. Letters 14, 111. 
McGuire, R. E., Anderson, K. A., Chase, L. M., Lin, R. P., and McCoy, J. E. : 1972, Trans. AGU 53, 108f 
Palmeira, R. A. R., AUum, F. R., and Rao, U. R.: 1971, Solar Phys. 21, 204. 
Parker, E. N. : 1963, Interplanetary Dynamical Processes, Interscience Publishers, Chapter 8. 
Simnett, G. M.; 1971, Solar Phys. 20, 448. 
Simnett, G. M. : 1974, Space Sci. Rev. 16, 257. 
Smerd, S. F.: 1970, Proc. Astron. Soc. Australia 1, 305. 
Smith, D. F.: 1970, Solar Phys. 15, 202. 



THE FLASH PHASE OF SOLAR FLARES : SATELLITE OBSERVATIONS OF ELECTRONS 221 

Smith, D. F.: 1972, in R. Ramaty and R. G. Stone (eds.), Proc. Symposium on High Energy Phenomena 
on the Sim, Goddard Space Flight Center, Greenbelt, Maryland, September, 1972, p. 558. 

Sullivan, J. D. : 1974, J. Geophys. Res., to be published. 

Syrovatskii, S. I. and Shmeleva, O. P. : 1972, Soviet Astron. AJ 16, 273. 

Trubnikov, B. A.: 1965, Rev. Plasma Phys. I, 105. 

Wang, J. R., Fisk, L. A., and Lin, R. P. : 1971, Conf. Papers, 12th International Conference on Cosmic Rays, 
Hobart, Tasmania, Australia, 2, 438. 

Wild, J. P. : 1950, Australian J. Sci. Res. A2, 541. 

Wild, J. P., Murray, J. D., and Rowe, W. C. : 1954, Australian J. Phys. 7, 439. 

Wild, J. P., Smerd, S. F., and Weiss, A. A.: 1963, Ann. Rev. Astron. Astrophys. 1, 291. 

Wild, J. P. and Smerd, S. F.: 1972, Ann. Rev. Astron. Astrophys. 10, 159. 

Zaitsev, V. V., Mityakov, N. A., and Rapoport, V. O.: 1972, Solar Phys. 24, 444. 



fslOfi Oo OJJ- -■'/•■" . ■ T)^^ 



Mapping of Lunar Surface Remanent Magnetic Fields 
by Electron Scattering (^ 

R. P. Lin, R. E. McGuire*, H. C. Howet, K.A. Anderson* 

Space Sciences Laboratory 

University of California 
Berkeley, California 94720 

and 

J. E. McCcy 

Lyndon B. Johnson Space Center 
Houston, Texas 77058 

We present preliminary results of a new technique to detect and 
measure weak and small scale lunar magnetic fields (Howe et_al. ). 
This technique makes use of the fact that charged particles are easily 
mirrored or scattered in moving to a region of increased magnetic field 
strength. The particles, in effect, provide a probe along the external 
magnetic field line down to the lunar surface. This probe is sensitive 
to increases in field strength along its path. If no surface magnetization 
is present, the particles are guided by the external magnetic field into 
the lunar surface where they are absorbed (except for a few percent which 
are Coulomb backscattered from surface material). If surface remanent 
magnetism is present, the total field strength increases as the particles 

*Also Physics Department. 

tPresent address: Thermonuclear Division, Oak Ridge National Laboratory 
Oak Ridge, Tennessee 37830 



enter the region of remanent magnetism, causing a fraction of the particles 
to mirror or backscatter with an intensity that increases with the average 
strength of the total surface field. 

This effect has repeatedly been observed for electrons by the 
Apollo 15 and 16 Particles and Fields Subsatellites (PFS.l & 2). When 
the reflections are strong the on-board magnetometer records a distinct 
magnetic effect. All the effects we attribute to electron mirroring and 
scattering are fixed with respect to lunar surface features. The spatial 
resolution of this technique is limited only by the gyro-radius of the par- 
ticles used as probes. Electrons, because of their small gyro-radii, 
are ideal for this application. 

The backscattering of the electrons depends on the scale size of 
the region of remanent magnetism. Monte Carlo simulations using direct 
force equation trajectory calculations have been performed to estimate 
the scattering from various magnetic configurations. The reflection co- 
efficient for fluxes in the 45° -90*^ pitch angle sector is found to be well 
approximated by the assumption of adiabatic particle motion under the 
average surface field (averaged over the electrons gyro orbit). This 
assumption provides a simple way of estimating the total field strength 
at the lunar surface: 



2 

B - = B-/sin a 
surf c 



3. 



where a , the limiting pitch angle to be backscattered is calculated from 

the observed ratio of fluxes R between the incident and returning 45° -90° 

pitch angle fluxes 

90° 
J j(a) sina da 



90° 

r i(a) sina da 
45° 

where B is the ambient magnetic field, a is the electron pitch angle, 

i(a) is the directional electron flux, B . = I B_ + B I . 
•' surf ' rem' 

Using the ratio of backscattered to incoming electron flux at 14 

keV we have mapped the remanent fields (B ) near the PFS-2 ground 
'^^ rem '' 

track with a spatial resolution of ~ 40 km and a sensitivity of 0. 1 y 
average field over the 40 km x 40 km resolution element. The results 
are shown in the form of color overlay maps (Figure 1) for the two 
cases of the external field pointing into and out of the lunar surface (B. 
and B ) respectively. 

The 14 keV electron maps confirm the generally stronger fields 

2 
reported in the lunar highlands reported fcy Sharp et al . and also show 

evidence of sharp changes in the lunar remanent magnetism in less than 

3 

one resolution element (40 km). 

During real time tracking of the PFS, the i keV electron flux is 
read out five times during the satellite spin period of five seconds. These 
high temporal resolution, low energy data allow mapping of the surface 
remanent fields to a spatial resolution of better than 10 km. Some prelim- 



4 
inaiy results of the 2 keV mapping have been presented elsewhere. This 

/ -7 

technique can be extended to fields as weak as 10 Gauss at the lunar 

surface and to spatial resolution of <^ 3 km. 



Acknowledgments 

We thank P. J. Coleman and C. T. Russell for supplying the mag- 
netometer data. This research was supported in part by NASA Contract 
lSIGS-7127 and Grant NGL-05-003-017. 

References 

1. Howe, H. C, R. P. Lin, R. E. McGuire and K. A. Anderson, Ener- 
getic electron scattering from the lunar remanent magnetic field, 
Geophys. Res. Lett., 1^, 101, 1974. 

2. Sharp, L. R. , P.J. Coleman, B.R. Lichtenstein and C. T. Russell, 
Orbital mapping of the lunar magnetic field. The Moon, !_, 322, 1973. 

3. McCcy, J.E., K.A. Anderson, R. P. Lin, H. C. Howe and R. E. 
McGuire, Lunar remanent magnetic field mapping from orbital 
observations of mirrored electrons. Lunar Interactions Conference 
(Abstract), p. 52, 1974. 

4. Anderson, K.A. , R.P. Lin, R. E. McGuire, H. C. Howe and J. E. 
McCoy, High resolution mapping of the lunar surface remanent mag- 
netic field by energetic electron scattering. Lunar Science VI, 
Abstracts of the Sixth Lunar Science Conference, p. 12, 1975. 



/ 



Figure Caption 

Figure 1. This figure shows lunar surface magnetic field strengths 

obtained from the electron scattering technique (see text, page 3). 

The field strengths are average values over a 40 km x 40 km 

-5 
region, and are plotted from < 0. ly (ly = 10 Gauss) to > 1. Sy 

increasing try factors of two. The data shown are from magnetotail 

and magnetosheath passes of the Apollo 16 Subsatellite. Separate 

maps have been constructed for times when the external magnetic 

fields are directed outward and inward with respect to the lunar 

surface. 



Luncxr ScienGe VI, The Lunar Science Institute, Houston C'l 3 



THE MATURATION OF LUNAR DUST GRAINS. J.L. Bertau>t°, J. P. Bibring*, 
J. Borg*, A.L. Burlingame''', Y. Langevin*, M. Maurette*, F.C. Walls'*". °Laboratoire 
d'Aeronomie du CNRS, 91 Verrieres-le-buisson. *Laboratoire Rene Bernas, 91405 
Orsay. ''"Space Science Laboratory, UC Berkeley, 94720 California. 

I. INTRODUCTION. As a result of lunar "weathering" processes active at the inter- 
face between the moon and its space environment, "maturation" proceeds both in 
modifying the surface physicochemical properties of lunar diist grains and in 
injecting new grains in the regolith. .In this report we first present a "dyna- 
mical" history of maturation obtained by "theoretically" generating the indi- 
vidual motions of dust grains in the top layers Of the lunar regolith. Then we 
use results of simulation experiments to define solar wind maturation as well 

as to propose a new sampling technique for extracting grains in lunar core tubes 
which should greatly help in deciphering the past activity of this type of ma- 
turation. Finally we try to correlate several bulk properties of the lunar 
regolith to specific "weathering" processes active during maturation. 

II. THE SIMULATED "DYNAMICAL" HISTORY OF MATURATION. 'r 

In our Solmix computations (1) intended to predict the most probable motion 
of lunar dust grains in the regolith, we define 2 parameters, Aj.„ and N^, which 
are the key "dynamical" factors involved during maturation. 

11. 1. AjQ, the lunar "skin ". Let us consider a grain with a radius, r, at 

an initial depth, d^, in the top strata of the regolith. As a result of the gar- 
dening due to the meteorite rainfall such a grain has a probability, S(r, d^, 
^o " "^b' "s^ '^° S®"*^ exposed more than ng times on the top surface of the rego- 
lith, during a time interval, Xj^ = 25. 10^ years, which represents the meanlife 
of the top strata against burial by another strata (see chapter III.l, in ref.l). 
From the sharp drop of S(ng) when d^ increases we infer the following conclusions: 
1. when d^ ~ 5mm the 50 y-grains (r '^ SOy) have a high probability (~ 80%) of 
being exposed in more than 5 different orientations (ng > 5) at depth ; 2.S(ng) 
decreases with the size of the grains and only 50 % of the 1 y-grains within the 
same_surface layer (d^ ~ 5mm) have been exposed at least once at depth 0, during 
the Xjj time interval. However as soon as the 1 y-grains (r 'v< ly) get exposed at 
depth they suffer additional changes in orientation (= 0.1 per year) due to 
the momentum imparted by the lunar winds ; 3 . therefore we will define this most 
superficial layer of the top strata with a thickness "^ 5mm, as the lunar "skin", 
Argj in which maturation will proceed as a high proportion of grains, at depths 
dQ ~ 5mm, get homogeneously exposed on "all their faces" to lunar weathering 
processes. 

11. 2. Ng, the number of "progenitor" top strata , through which the grains 
have been cycled before their most recent deposition in the regolith - for stra- 
ta with a thickness Ag ~ 1cm, Ng has a value of about 2.5/10^ years (ref.l. 
Chapter III.l). This dynamical factor is also involved during maturation for the 
following reasons : i. the necessary condition for a "fresh" 50 y-grain just 
admixed at any depth into the top strata to proceed to maturation is to get in- 
corporated within Al5, and the probability of this event is - O.S.ALg/Ag. For 
an average value Ag = 3cm (ref.l, chapter III.l) such a grain should then be 
successively cycled through about 7 "progenitor" strata, to be incorporated wi- 
thin a lunar "skin" ; ii. during the Ng cycling, glassy grains are certainly 
injected in the regolith and accretionary particles could probably get stuck to /J'N 



■4 



43 



MATURATION OF LUNAR DUST GRAINS 
Bertaut J.L. et al. 



the external surface of the coarser grains. 

III. MATURITY INDICES 

It is difficult to define a meaningful experimental index of maturity. In- 
deed the "bulk" maturation of the lunar soil results from the combination of a 
variety of lunar "weathering" effects (implanted species and radiation damage 
coatings due to the solar wind ; solar flare tracks ; accretionary particles ; 
glassy agglutinates ; impact craters in the sub-micron range) which correspond 
to different processes. Furthermore the extent of maturation related to each 
one of these processes is likely to depend on both the size and the nature of 
the grains that are used to measure the index of maturity. 

This last difficulty is particularly well illustrated for solar wind matu- 
ration which only occurs for grains directly exposed at depth 0. In fact the 
active depth associated with this type of maturation is given by the thickness 
of the corresponding lunar skin (= 5mm). In any soil sample the index of solar 
wind maturation can be tentatively defined as the degree of saturation of its 
constituent grains with respect to solar wind effects. But from the previous 
definition of Al2> this index is a complex quantity. Indeed 50 y-grains are. ex- 
posed about 50 times longer in the solar wind than the 1 y-grains. Furthermore 
ilmenites will reach saturation levels at doses of solar wind ions that are 10 
times higher than those observed for the feldspars. Therefore on the lunar sur- 
face feldspars of any size "mature sooner than ilmenites, and we predict that 
most of the finest ilmenite grains will not get mature with respect to solar 
wind effects (ref.l, chapter II.3). In a given soil sample a "feldspar" index 
of solar wind maturity could then be estimated by measuring the proportion, F, 
of 1 y-feldspars showing an amorphous coating of solar wind radiation damaged 
material. If this proportion is already equal to the saturation value (100 %) 
one could rely on an "ilmenite" index of maturity determined by measuring the 
concentration of solar wind implanted species in the finest ilmenites. 

IV. THE PAST ACTIVITY OF SOLAR WIND MATURATION 

We first propose the following new technique for extracting dust grains in 
lunar core tubes : 1. several couples of strata showing well defined boundaries 
have to be identified at various depths in a lunar core tube ; 2. then in the 
lower stratum of a given couple, grains should be extracted up to a maximum 
depth, Al2 - ^"""» from the boundary with the upper adjacent stratum (Als samp- 
ling technique). A high proportion of these "Als" grains have been last exposed 
to the solar wind at a rather well known epoch, which corresponds to the time 
of deposition of their parent strata on the lunar surface. In addition for the 
feldspars of any size this "last" solar wind exposure was sufficiently long to 
both sputter away all previously acquired solar wind effects and to reload at 
saturation the grain "memory" with fresh effects, which thus reflect the average 
properties of the solar wind during the last ion implantation episode. The past 
activity of the solar wind could then be measured as already suggested (2) by 
using such "Aj^s" feldspars. 

V. EFFECTS OF MATURATION ON THE BULK PROPERTIES OF THE LUNAR REGOLITH. 

V.l. Albedo of the lunar regolith . The optical properties of the regolith 
are strongly affected by weathering processes active during the Aj^g ^"'^ ^s '^V 
cling of luflte" dust grains. To identify such processes we summarize below our 



MATURATION OF LUNAR DUST GRAINS 
Bertaut J;L. et al. 



albedo studies conducted as follow : the albedo. A, of size fractions and mine- 
ral separates extracted from soil samples showing different F index of solar 
wind maturity (see chapter III) is determined from '^ 1,300.8 up to 6,500 8 ; then 
possible correlations between the A values and several characteristics of indi- 
vidual grains from the corresponding sub-samples (measured as described in ref .3) 
are searched for. Our main results are : The albedo of a mature soil is only 
similar to that of its finest size fraction ; 2. the finest grains have no "dark" 
metallic coating (ref. 3, chapter lEI.l) and they are both enriched in feldspars 
and depleted in Fe-rich grains such as pyroxenes and glasses (ref. -3, chapter 
III. 5) ; 3. it seems that accretionary particles on the grains are enriched in 
opaque grains (ref. 3, chapter III.5-B>, ^. the finest grains are in fact aggre- 
gates of welde.d dust particles (ref. 3, chapter III.3-A) ; 5. the A values 
sharply drop when the F index increases above 20 %. On the other hand no clear 
correlation was found between A and either the proportion of glassy grains in 
the 5 y-residues or Al/Si ratios smaller_than_=_0^5. Therefore the darkening of 
a lunar soil with an Al/Si ratio S 0.5 is probably due to a mixture of grain 
aggregation, solar wind effects, and accretionary particles. 

V.2. Concentrations of solar wind implanted species in the regolith . yg 

have applied high resolution mass spectrometric pyrolysis techniques to feldspar 
and ilmenite targets, implanted with doses of He, G, N, and S ions ranging from 
5. 10^5 up to 10-'-° ions/cm^, at solar wind energies. (A) Helium_concentrations 
versus_dose : 1. the retention of He in feldspars, at the temperatures "evolved 
during the ion implantations (<100QC) is quite complex and follows two main 
courses : first He gets completely lost from the targets and then starts to be 
retained at a fliix value of about 3.10-^° ions/cm^ , which just corresponds to the 
formation of an amorphous coating of radiation damaged material on the feldspar 
(this feature probably reflects the transition from a "damage" to a "trapping" 
diffusion mechanism). But only =6% of the incident ions get thus retained up to 
an amount of ==3. 10-^^ ions/cm^ ; 2. in ilmenite the He concentration, increases up 
to a saturation value ,'i's(He) ==3.10^'' ions/cm'^ , where about 30% of the incident 
ions are effectively trapped into the target ; 3. from these features we first 
predict ¥s(Ar) values in the 10084 ilmenite separates analyzed by Eberhardt et 
al(4^) which well agree with the experimental determinations. In addition we re- 
ccn firm independently for ilmenite the solar wind sputtering rate (=0.05 A/year) 
that we estimated last year from an electron microscope observation of ly-grains. 
(B) Pyrolysis release Batterns_of_He,_C^ N, and S :1. all species start to be 
released at low temperatures (=150°C ) from the targets, with carbon being the 
most stable species; 2. the patterns exhibit release peaks that are only well 
defined for carbon ( bimodal CO release and trimodal CO2 release in feldspar ) 
and to a lesser extent in nitrogen ( trimodal release in ilmenite )'; 3. the rele- 
ase peaks broaden and get assymetrical for high doses , and they are generally 
shifted to higher temperatures when the ion energy increases ^3. carbon is the 
best "chemical" probe to investigate the properties of the ancient solar wind. 

REFERENCES. (1) G.Comstock et al. (1975), this volume .(2) J.Borg et al.(1974), 
in Solar Wind III, p. 68, UCLA. (3) J.Klossa et al. (1975), this volume .(H) 
Eberhardt P. et al. ( 1972) ,Proc. Lunar Sci.Conf. 3rd, p. 1821. 



ri 



^> 



v3 



KEROGEN STRUCTURES IM BECEMTLT-DEPOSITED ALGAL MATS AT l AGUMA MOBMONA, 
BAJA CALIK)RMIA: A MODEL SYSTEM FOR THE DETERMINATION OF 
KEROGEN STRUCTURES IN ANCIENT SEDIMENTS 



R.P. ?hilp and M. Calvin, Department of Chemistry, University of 
California, Berkeley, California 9^720 



Presented at the 2nd Environmental Biogeochemistry Conference, 
Biirlington, Canada, April 8-11, 1975 



■ABSTRACT 

Lagvma Mormona, Baja California, is dominated by an evaporite 
flat and hypersaline marsh environment which is characterized "by algal 
mats and zones of Salicomia and Bistichlis . Large quantities of 
organic material are accxxmulating because of the high salinity, which 
virtusilly eliminates the grazing and "burrowing activities of metazons 
which ingest and digest algal and bacterial components of the mat, 
and also the persistent anaerobic conditions with increasing depth. 

Kerogenous material isolated from these algal mats was subjected 
to chemical degradation treatment. Structural determinations of 
kerogens from ancient shales have often been thwarted by the complex 
mixtures of reaction products obtained. It was anticipated that 
in view of their age, kerogens in these recently deposited algal 
mats woTild be structurally less complex. Indeed chemical degradation 
of this material yielded reaction products less complex than those 
obtained from ancient kerogens. 

The major oxidation products isolated included dicarboxylic 
acids (C... ~ ^pp)> a-methyl-branched monocarboxylic acids (C,^ - ^2C? ^ 
normal monocarboxylic acids (C^p - C_-) and a series of isoprenoid 
acids dominated by phytanic acid. These results suggest that kerogenous 
material is present in these algal deposits in a very immature state 
and it resembles ancient kerogens to a certain extent. 



IMTRODUCTION 

Kerogen is a ubiquitous source of organic carbon on the Earth's 
surface, containing over three orders of magnitude more organic carbon 
than all the other organic carbon reservoirs combined (Sackett et_ al. , 
I97U). Kerogen has been defined in many different vays but in this 
paper the term kerogen refers to organic material in sediments , shales 
and rocks ■which is insoluble in organic solvents. The deposition of 
plants and animal remains in marine and non-marine environments and the 
alteration of this debris during subsequent geologic periods by 
numerous reactions produces a wide variety of carbonaceous materials. 
Oil'shsLles, kukersite, coorongite and torbanite represent different 
types of carbonaceous material containing various amotints of kerogenous 
organic material, from vhich high yields of oil ,can be produced at 
elevated temperatures. 

The geochemical, environmental and economical significance 
of kerogen has led to many attempts to reveal its chemiceil and physical 
nature, its method of formation and its ancient precursors. These 
investigations have been hampered not only by the insolubility and 
macromolecular nature of the substance but also by the fact that kerogen 
is not a xmiform molecule but most likely a conglomerate of various 
sub-units of similar, but varying molecular structures. Kerogen is 
both chemical and biologically very inert and therefore can be used 
as a "chemical fossil" in sediments. This term was used by Eglinton 
(1973) to describe various classes of organic compounds which are 
relatively stable under varying environmental conditions throughout 



long periods of geological time. An example of kerogen's potential 
as a chemical fossil vas given by Sackett et al» (197^) vho analysed 
amounts and isotopic composition of the organic carbon, which is 
95/^ kerogen, in sediments of the Ross Sea, Antarctica. From this 
study it was shown that much of the sedimentary organic carbon in 
the sediments is derived from the rocks being eroded by glaciers 
on the Antarctic continent. 

It is now generally agreed that many oil shales were formed 
by growth and deposition of algae, and that conditions of sedimentation, 
compaction and lithification were not too dissimilar from those existing 
at present. Thorne and co-workers (l96if) at the U.S. B\ireau of Mines 
aptly siommarized the situation in the following way: "Oil shale was 
formed by the deposition and lithification of finely divided mineral 
matter and organic debris in the bottom of shallow lakes and seas. The 
organic debris resulted from the mechanical and chemical, degradation 
of small aquatic algal organisms." If indeed this is correct then 
as Cane C1969) has noted, with some surprise, it is unusual that we 
fail to observe the initial stages of kerogen formation in the contemporary 
environment. Although as he adds this may be due to the infrequency 
of the peculiar enviroiunental conditions for favorable vegetal growth. 
Bradley (1966, 1970) has suggested the reason for failing to observe 
these initial stages of kerogen foimation is due to the fact that the 
rate of deposition of kerogenous algal ooze is less than 1 mm per 
century for the dry material. However under certain specialized 
conditions profuse algal growth does occur and leads to the formation 
of Coorongite and BEilkaschite which represent an early stage in the 
formation of algal kerogen. Cane (1969) has suggested therefore 



-3- 



that Coorongite can "be regarded as the "peat" stage in the "coalifi cation" 
of algal shales and proposed that a study of the nature of this 
intennediate shoiild provide important information on the natiire of 
the more mature and inert kerogen. Thus from an examination of 
living algae and recent algal deposits it should be possible to get 
additional information on the initial stages of kerogen formation. 

Consequently a combined study of the soluble and insoluble 
organic matter present in recently-deposited algal mats from Laguna 
Mormona, Baja Ca3.ifornia, has commenced. The soluble lipid material 
in these mats vill be discussed elsevhere in this volume by Eglinton 
and co-workers whereas we will concentrate on the insoluble or kerogenous 
fraction of the mats. 

Blue-green algae are especially interesting because of their . 
ability to survive in environments which favour the preservation 
of organic matter such as hypersaline and reducing environments. 
Contemporary algae are also of interest since the search for the 
origins of unicellular life on Earth has now reached the point where 
some of the micro structures referred to as exhibiting "alga-like" 

and "filamentous" morphologies occur in cherts from South Africa that 

9 

are older than 3 eons (3 x 10 years, Schopf and Barghoorn, I967). 

In order to get a clearer picture as to the origin and nature of these 
possible organisms it is essential that the nature of modern prokaryotic 
algae is completely understood in the first instance. 

The area at Laguna Mormona is characterised by extreme local 
variations in sedimentological, geochemical, and biological properties 
(Vondeer Haar, 1973 )• Semi-arid climatic condtions and restricted 
water movement from the ocean have combined to produce an evaporite flat 



and hypersaline marsh environment. A barrier dune ridge separates the 
sea from a 100 m wide marsh which is characterised by algal mats. 
Mucilaginous algal laHiinae are disrupted by plant roots, early diagenetic 
growth of aragonite granxiles and also by dessication cracks. Large 
quantities of organic matter are slowly accximulating because of the 
high salinity which inhibits organisms that normally consume and degrade 
the organic material. ("Algal mat," in general, refers to a cohesive 
fabric of filaments produced by a community of cyanophytes involving 
several species combined with different amounts of sediment (Logan 
at al . , I96U). The medn mat-producing genera are Aphanocapsa , 
A phanothece and Entophysalis among the coccoid, and Oscillatoria , 
Lyngbya , Micro cole us and Sehizothrix among the filamentous cyanophytes, 
althovigh green and red algae, animals and abundant bacteria are often 
included in the community (Golubic, 1973).) 

The intertidal mats examined from Laguna Mormona are characterised 
by Microcoleus chthonoplastes and Lyngbya aestuarrii . Sediment binding 
by M. Chthonoplastes is common to a wide variety of environments and 
no particular mat type can be consistently attributed to it. Lyngbya 
aestuai'rii has also been observed in arid subtropic bays such as 
Shark Bay and the Persian Gulf. In those environments the flat 
mats covering the floors of tidal pools and tidal channels are laminated 
structiires with different proportions of trapped sediment. The mats 
often crack during draining, and shrinking of the algal fabric creates 
polygons of different sizes (Golubic, 1973). 

Within "the intertidal aree,s at Laguna Mormona several factors 
appear to influence the distribution and growth of the mats. They 
are chjiracterised by the alteration of the water level and exposure 



->- 



to air. A chemical gradient "between the limit of the tidal flooding 
and the evaporite sequence, and freshwater inflxix leads to changes 
in mat distributions. Differences in mat morphology can he partially 
accovmted for hy the amount of sediment deposited over the mats hy 
water movement. 

The diverse nature of the brganosedimentary structures within 
the mats can readily he appreciated hy summarizing the three general 
areas of importance that should he considered when examining these 
structures: (l) the nature and species composition of the algae commimity; 
(2) the interaction of the community with major environmental variahles, 
such as location in respect to tides, currents, sedimentation rates, 
light, drainage and oxygen supply; and (3) the hiological dynamics within 
the community halances hetween the rates of primary production and 
hacterial decomposition (Golubic, 1973). 

As mentioned ahove there have heen several studies directed 
at determining the structure of kerogen in smcient shales and sediments, 
in particular the Green River oil shale (Robinson et al. , 1953) 1956, 
1961, 1963; Burlingame et al . , 1968a, 1969h; Djuricic et_ al . , 19Tl) . 
Djuricic and co-workers (1971 ) have also examined a collection of 
kerogens from ancient sediments of different geographic origin in 
an attempt to correlate variations in kerogen structures with the 
history and environment of the shale and thus give valuable information 
concerning the chemical formation of kerogen. All of these studies have 
involved degradation of the kerogen, either hy oxidation, reduction, 
hydrolysis or pyrolysis techniques, followed hy structural identification 
of the individual components of the degradation mixtures. From this 
data it is then possible to attempt the reconstruction of a structure 



-6- 



for the original kerogen. The various reagents that have "been used 
in the oxidation studies include chromic acid (Burlingame et^ al. , 
1969a), hydrogen peroxide (Downs and Himus , 19I1I), ozone (Jones, 
1922) and potassium permanganate (Robinson et al . , 1953). In the 
majority of these studies the mixtures of the degradation products 
obtained have been complex and although it has normally been possible 
to analyse them by techniques such as computerized-gas chromatography- 
mass spectrometry after initial fractionation and derivatisation, it 
is still difficult to construct anything but a preliminary model for 
the kerogen. 

Thus it vas anticipated that similar degradation studies of 
the less mature kerogenous material in these recently deposited 
algal mats vould provide answers to the following questions: 

(a) Is there any kerogen-like material in these recently 
deposited algal mats? ^ 

(b) Will degradation studies of young kerogens give information 
as to the structure and nature of ancient kerogens? 

(c) ¥iat are the initial steps in the formation of kerogen? 

(d) Are changes in complexity of the kerogen observed with 
changes in depth within these algal mats? 

(e) Can kerogen-like material in recently deposited algal 
mats be used as a chemotaxonomic indicator? 

EXPERIMENTAL 
(i) Sample collection 

A box coring device was used to collect a sample of the 
algal mats to a depth of approximately eight inches. This was divided 



-7- 



into three sections which vere transferred to clean glass bottles, 
capped and su"bseq.uently stored at 0°C until required for examination 
and extraction. No isopropanol vas added to the samples immediately 
after collection as it vas felt that changes due to microhial alteration 
vould he minimal if the samples were stored at 0°C. 

(it) Sample preparation 

To determine whether or not there vas any kerogen-like material 
produced by degradation and diagenesis of the algal mat and also 
get an idea of its structure, it vas decided in this preliminary study 
to use an oxidative degradation technique similar to that used by 
Burlingame and Simoneit (1968b) in their oxidation studies of Green 
River oil shale kerogens. Almost every published vork on the study 
of kerogen uses a different method for the preparation of the samples 
making it extremely difficult to compare results of various workers. 
Forsman and Hunt (1958) proposed an acid digestion of shales with 
consecutive treatments vith HCl, HNO_ and HF to remove carbonates, 
pyrites and silicates respectively. Burlingame and Simoneit (1968a) 
however used zinc dust and 6m HCl to remove siilphides and free svilphur. 
Lavlor and co-workers (I963) advocated the use of lithium aluminum 
hydride for quantitative pyrite removal Eilthough this results in 
specific alteration of kerogen functional groups. One important 
factor to be taken into consideration \d.th all these methods is 
the possibility of alteration of the organic kerogen by the action 
of strong mineral acids. 

The mineral content of the algal mats was found to be 
predominantly cai'bonate and as a consequence of this was treated 



-8- 



only with 6M HCl. The method of isolation of the kerogen-like material 
is shovn in Figure 1. After removal of supernatant water the sample 
was refluxed for 6 hours with 6MHC1. It was centrifuged and the 
residue exhaustively extracted for a total period of two weeks with 
the following solvents: toluene/methanol (l:l), methanol and finally 
toluene. 

The supernatant aqueous fraction was set aside for examination 
of its amino acid, lactone and more polar dicarhoxylic acid content 
at a later date. A more detailed study on the lipids in the total 
organic extract of the algal mat has teen carried out by the Organic 
Geochemistry Unit at Bristol and these results will he reviewed hy 
Professor Eglinton elsewhere in this volume. 

The resulting residue, hereafter referred to as kerogen, was 
washed with triple distilled water and allowed to dry under vacuo 
at room temperature. It should he mentioned at this juncture that 
this residue was not subjected to any fui-ther treatment, such as 
HF treatment or saponification. However subsequent work with this 
algal mat sample has shown that HF treatment does not have any noticeable 
effect on the qualitative or quantitative nature of the results 
described herein (R.P. Philp, unpublished results). 

Ciii.) Oxidative reactions 

The kerogen residue was subjected to successive chromic 
acid oxidations (successive reaction times used: 3 and 6 hours). 
^.3 6 of kerogen residue (after hydrolysis and extraction) was 
refixixed 3 hours with 314 chromic acid in 3M sulftiric acid. The 
residue was then filtered off, washed with water and extracted 



-9- 



three times each, first vith heptane and then diethyl ether, using 
ultrasonication to insure thorough extraction (Figure 2). The spent 
chromic acid solution vas also extracted with heptane and then ether. 
The respective extracts were comhined and the acids extracted from 
them with 333 KDH solution. The acids were recovered and esterified 
\rlth BF /MeOE and the esters of normal acids were separated from 
those of "branched-cyclic acids hy clathration with urea. The total 
acid extracts from the 6 hour oxidation were not subjected to urea 
clathration. 

All analytical gas-liguid chromatography (GLC) was carried 
out on a Perkin Elmer Model 900 gas chromatograph. The total, normal 
and branched/cyclic fractions were gas chromatographed on a 10 ft. 
X l/l6 in. i.d. stainless, steel column, packed with 3^ Dexsil 300 
on Gaschrom Q and programmed from TO to 280°C at J|° /minute with a 
helium flow rate of 15 ml/minute. (iTrjiese same GLC conditions were 
used throiighout this study. ) The various components of the mixtures 
analysed hy GLC were identified by their retention times, coinjection 
of standards , and low resolution mass spectra obtained by combined 
gas chromatographj'--mass spectrometry (GC-MS). Combined GC-MS 
analyses were carried out on a DuPont ^92-1 instrimient interfaced 
with a Varian Aerograph Model No. 20^ equipped with linear temperature 
programmer. The column used for the GC-M3 analyses was a 30 ft. x 
0.03 in. i.d. glass capillary column packed with 1% OV-1 coated 
on 80-100 mesh Gas Chi-om Q. The mass spectral data ^ms acquired and 
processed using a DuPont 21-09^ data system. 



RESULTS 



-10- 



The elemental analyses of the algal mat, the kerogen residue 
and the residues after the various oxidations of the kerogen residue 
are given in Table 1. The yields of total and acid extracts for 
all extraction steps are listed in Table 2. 

(l ) Exhaustively extracted fatty acid fractions 

As mentioned a detailed description of the soluble fatty 

acid extract can be foimd elsevhere in this Volume (Cardosa et^ al . , 

1975) • However a preliminary examination of this fraction by 

computerised-gas chromatography-mass spectrometry (C-GC-MS) revealed 

the normeil fraction to predominantly consists of a homologous series 

of normal saturated fatty acids in the range C^ • - C^^ vith maxima 

at C^g and C^^. The presence of mono-unsaturated C^- and C « fatty 

acids vas also detected. Minor quantities of iso- and anteiso-C, ,. 

\ 15 

acids vere observed in the branched/ cyclic fractions along with 

relatively large quantities of a higher molecular weight acid tentatively 

Identified as a C„p~triterpanoic acid. In view of the discussion 

below it is important to note that no dicarboxylic acids could be detected 

in this fraction by macs fragmentography (Kites and Biemann, 1970) 

or interpretation of Individual spectra. 

Cii) 3 hour oxidation 

(a) Branched-cyclic fractions 

The heptane fraction consisted mainly of a series of isoprenoid 
mono-carboxylic acids dominated by C^j^, C^^, C^^, C^ , C^ , C^^ acids 
'(peaks 1, 2, 3, 5» 7» 8 respectively in Figiire 3) and their relative 



distribution is clearly illustrated in the lower gas chromatogram shown 
in Figure 3. Two other "branched aliphatic carboxylic acids (C, „ 
and C, o, peaks k and 6 respectively in Figure 3) were also present. 
The diethyl ether extract was dominated hy a series of mono-methyl 
branched dicai-boxylic acids in the range Ci - Cg* No aromatic, 
cyclic or keto acids could be detected in either the heptane or the 
ether fraction (Figure k). 

(b) Kormal fractions 

The normal heptane extract was dominated by a series of normal 
mono carboxylic acids in the range C.p ~ Cp„ with a maximiam at C y-. 
A series of saturated unbranched dicarboxylic acids were present 
in minor quantities in the range C - C_„ with a maximum at C^ . 
A second series of saturated branched dicarboxylic acids (range C^^ 
- C,c» Biax C^o) "^^^ also present in minor quantities. The other 
homologous series identified in this fraction was a series of 
o-methyl-br£uached monocarboxylic acids in the range C, _ - C^. with 
a maximum at C^ (Figure 3). 

The ether extract was dominated by the more polar unbranched 
dicarboxylic acids in the range Cn to C_„ with a maximum at C, _. 
The acids in the range C^ _ -> C^„ were present only in minor quantities. 
There was also another major series of saturated branched monocarboxylic 
acids in this fraction in the range C^ - C with a maximum at C . 

(iii) 6 hour oxidation 

These fractions were not subjected to urea adduction due 
to the small quantities of material available. The heptane extract 
did not give any resolvable peaks by GC and was therefore not further 
analysed by GC-MS. The ether extract basically consisted of two homologous 



-12- 



series. The first vas a series of .normal acids in the range C^„ 

- CpQ vith a maximum at Cpi , and the other a series of a,a)-dicarboxylic 

acids in the range C^o ~ ^ph 'with a maximtim at Cp-. 



Discussion 

Before commencing the discussion on the qualitative aspects 
of these results it is valuable to examine the quantitative resiilts 
shown in Tables 1 and 2. Firstly from Table 1 it can be seen that 
after only the 3 hour oxidation the organic carbon content of the 
kerogen residue has been reduced to 0.86^ and is further reduced 
to 0.5^^ after 6 hotirs. Firstly this suggests that there is kerogenous 
material in this very young algal, debris vhich can be degraded by 
oxidation. Secondly this kerogen appears less resistant to oxidative 
degradation than the kerogen from Tasmanian tasmanite. In this case 
90 hours vere required for the organic carbon content to be ^reduced 
to the value obtained for the algal kerogen after a 3 hour oxidation 
period (Simoneit and Burlingame, 1973). 

Trom Table 2 several important factors emerge, primarily the 
fact that 58.7 g of material has been removed in the initial hydrolysis 
experiment. This suggests the presence of large amounts of carbonate 
in the algal debris. A certain amount of lipid material will also 
be water soluble and hence not accountable for in this particular work 
up scheme. The majority of degradation products are produced after 
the 3 hour oxidation, once again suggesting that the kerogen nucleus 
is less resistant to oxidation than the kerogens from older shales. 
.The residue remaining after the 6 hour oxidation is predominantly 
inorganic silicates as shown by X-ray fluorescence measurements. 



Again the discrepancy in the materials balance is due to the production 
of catrbon dioxide and vater soluble products during the oxidation 
reactions. It is intended that future experiments vill be directed 
towards permanganate oxidation of the algal kerogens using a method 
similar to that described by Djuricic and co-workers (l97l) which 
includes removal of the products from the oxidative environment 
as soon as they are formed. 

From these results it appears that the nucleus of this kerogenous 
material is predominantly a system of cross-linked polymethylene 
chains of varying chain lengths and various degrees of branching. 
The kerogen appears to be highly aliphatic, only trace amounts of 
aromatic acids were detected. It would also appear that condensed 
to this system on the periphery of the nucleus are unbranched hydrocarbon 
chains and also isoprenoid chains which when oxidized give rise to 
the normal and isoprenoid acids respectively. The fact that less 
time is required to completely oxidize this immature kerogen-like 
material would suggest that it is not a very highly condensed system 
as some of the more mature kerogens appear to be. It also suggests 
that the cross linkages are more susceptible to oxidation than in 
the older kerogens. In the soluble lipid fractions there are relatively 
large amo\ints of cyclic acids, such as the C_p triterpanoic acid 
mentioned above. However only trace amovmts of cyclic acids could 
be detected in the products from the kerogen oxidation. This suggests 
that the first stage in the formation of the kerogen is the condensation 
of the functiohalized aliphatic lipids to give the cross-linked 
polymethylene nucleus. The branched dicarboxylic acids and isoprenoid 
acids could either be condensed on the system at its periphery or 



-14- 



alternatively at this very early stage in the kerogen formation coxild 

be trapped vithin the polymethylene matrix prior to condensation. 

The most prohahle source of the isoprenoid acids is the phytol side 

of chlorophyll. Simoneit and co-workers (personal comraionication) 

have shown by stereochemical determinations that this indeed is 

the case vith the Green River Shale. The mono-methyl branched dicarboxylic 

acids from the 3 hotir oxidation could possibly arise from the mixture 

of 7~ and 8-methyl-heptadecanes vhich are known to be the major 

hydrocarbon constituent of blue-green algae (Han et_ al . , 1968). 

Again with this young immature kerogen these constituents could 

be entrapped within the polymethylene matrix and on oxidation give 

rise to the branched dicarboxylic acids detected in certain fractions. 

The results of this preliminary study have indicated that 
there is kerogenous-like material present in these recently deposited 
algal mats whose structtire bears certain similarities to that of more 
mattire and inert kerogens. However the problem still arises as to 
the method of formation of the kerogen nucleus in these algal mats. 
It also remains to be shown whether or not this material is formed 
by simple condensations of soluble unsaturated lipids known to be 
present in the algal mats or alternatively as suggested by Oehler 
and co-workers (l97^)» intracellular chlorophyll molecules might 
become grafted onto cellular macromolecules through ester and related 
linkages and these grafted pigment complexes may become incorporated 
into the insoluble kerogen fraction. 

CONCLUSIONS 
(1) On the basis of the degradation products obtained it 



-15- 



can be said that a kerogen like material is formed early on in the 
deposition of the algal mats. 

(2) The main kerogen nucleus seems to consist of polymethylene 
chains vith some cross linking, a small amount of aromatic material, 
plus uhbranched material on the periphery. 

(3) The kerogen nucleus is probably derived either from 
condensation of \insaturated oxygenated compounds or even the chlorophyll 
moelty. 

(U) The presence of relatively abundant quantities of phytanic 
acid suggests that this originates from the chlorophyll and is ester-linked 
to the kerogen nucleus. 

(5) To expand the idea that kerogen is being formed rapidly 
a depth study of kerogens from these algal mats will be undertaken 
to see if the degradation products show increasing complexity with 
depth. 

This initial study has provided some answers to the questions 
asked above but until further samples are examined it will not be 
possible to say whether the kerogen can be used as a chemotaxonomic 
indicator or whether there are changes in its complexity with changes 
in depth. 

Two very important questions which still remain unanswered 
relate to (l) the method of kerogen formation and (2) the types of linkage that 
hold the kerogen matrix together. To provide an answer to the first 
question is difficult. One way to study the short term fate of 
biolipids is to use C-labelled lipids and incubate them in the 
sediment for a period of severeO. months or more. However in order 
to observe the incorporation of these biolipids into the kerogen 



matrix would talie an impractical period of time . On the second question 
one can speculate and say that there are ether linkages or other types 
of heteroatom linkages in the kerogen which are attacked on oxidation 
with chromic acid, but one important point to raise here is what 
are the differences "between the linkages in this algal kerogen which 
appear to he readily attacked hy chromic acid and those in ancient 
kerogens which are fairly resistant to oxidative degradation? Is 
it merely the type of cross linkage, or is it due to that fact that the 
older kerogens are more highly condensed and thus potential sites 
of oxidation more sterically hindered? 

It is anticipated that hy looking at other algal kerogens and 
also other slightly older kerogens the answers to these questions 
and others may hecome apparent. 



ACKNOWLEDGEMENTS 

We thank Mr. Stephen Brown for assistance in obtaining the 
GC-MS data and Ms. Adrienne Ross for typing the manuscript. We also 
wish to thank Di'. S.W. Awramik and Mr. B. Simoneit for providing 
critical comments on the manuscript. This vork was ftmded hy NASA 
grant number NGL 05-003-003 and the DuPont data system was purchased 
on National Cancer Institute contract #NCI-FS-(7l)-58. 



FIGUBE CAPTIONS 

Figure 1. Initial extract and fractionation scheme used to prepare 

kerogen residues from the recently-deposited algal mat sample. 

Figure 2. Oxidation scheme used on insoluble kerogen fraction from 
the algal mats. 

Figure 3. Gas chromatograms of the heptane soluble normal and branched/ 
cyclic acid esters isolated from the 3 hour oxidation of the 
algal kerogen (GG conditions are given in the text). Only 
the major components in each fraction are labelled in this . 
Figure. In the upper trace the carbon numbers of the normal 
fatty acids are indicated by the arabic numerals and the 
monomethyl branched acids indicated by the primed arabic numerals. 
In the lower trace peak numbers 1, 2, 3, 5s 7» 8 correspond to 
isoprenoid acids and numbers h and 6 to branched acids 
vhose structures have not been assigned as yet. 

Figure k. Gas chromatograms of the ether soluble normal acid esters 
isolated from the 3 hour oxidation of the algal kerogen (GC 
conditions are given in the text). The primed arabic numerals 
refer to the carbon number of the normal dicarboxylic acid 
esters . 



Algal mat 
sample 



I 

Supernatent 
aqueous 
fraction 



(1) 6M HCl (500 ml) - 6 hr reflux 

(2) Centrifugation 



Algal mat 
residue 



Extract vith 
diethyl ether 
(3 X 100 ml) 



Exhaustive extraction 
vith organic solvents : 

(1) MeOH/PhCH (l:l) 

(2) MeOH ^ 

(3) PhCH^ 



Ether 
soluble 
material 



Aqueous 
fraction 



Organic 
extract 



"Kerogen" 

type 

residue 



"Kerogen" 
residue 



Cl) Oxidation with 3M chromic acid in 
3M H2SOIJ for varying periods of 
time (3 hr, 6 hr) 

(2) Centrifugation 

(3) Kerogen residue washed with HpO 

{k) Kerogen residue extracted with 
heptane followed by ether 

(5) Spent chromic acid solution extracted 
with heptane and ether and respective 
extracts combined with those from {k) 



Total ether 
extract 



Kerogen 
residue 



Acids 



Neutrals 



I 

Nonaal acids 
as methyl 
esters . 



Total heptane 
extract 



KOH extraction 



(1) BF /MeOH 

(2) Urea clathration 



i 

Branched/ 

cyclic 
acids as 
methyl esters 



I 

Acids 



KOH extraction 



Neutrals 



(1) BF MeOH 

(2) Urea Clathration 



Normal acids 
as methyl 
esters 



Branched/ 

cyclic 
acids as 
methyl esters 



o 

CO 



< 



o 



o 
to 



o 



"3 \ 



u 



R 



Lo 



3SN0dS3H ti0i03i3a 



o 

a. 
w 
ui 



o 



o 

UJ 



UJ 

o 



16 
I 



NORMAL FRACTION 




15' 
I 

16 
15 1 



18 
I 



17' 



17 
/ 

18' 
\ 



IS'P ',' 



I9'i 



y 



V 



21 





BRANCH ED- CYCLIC FRAr T 1 N 




— I — 
20 



TIME CMIN9 



10 



— I — 
60 



XBL 7411-8575 



Table 1. Elemental analyses of algal mat and kerogen residues at the 
various degradation steps. 



Dried algal Kerogen After 3 hour After 6 hour 
mats residue oxidation oxidation 



t Total carbon content 

* Total organic carbon content 

** By difference 



c 


9.3t 


10.31* 


0.86* 


• 0.3h* 


H 


1.8 


1.59 


i.n 


0.82 


W 


0.38 


0.7^ 


0.10 


0.03 


s • 


0.12 


0.52 


0.it5 


0.08 


Residue 

i 


67.9 


79.8 


88.3 


93.5 


1 0** 

! 


20.5 


7.0U 


9.18 


5.03 



Table 2. Extract yields from extraction and oxidations of the algal 
mat sample. 



Sample 



Totals Acid fractions (mgs ) 
(extracts or Heptane Ether 
residues ) soluble soluble 



1. Dried algal mat 

2. I^drolysed and exhaustively 
extracted mat (i.e, kerogen 
residue) 

3. Soluble lipid extract from 
.hydrolysed (l) 

h. 3 hour Oxidation of (2) 

5. 6 hour Oxidation of residue 
from (U) 

6. Residue after 6 hour 
Oxidation 



63 g 



1*.3 B 



5^ mg 


39* 




1^9 mg ■ 


18 


95 


2h mg 


2 


9 


1.9 g 




\ 



7. Total solvent solubles and 
residues recovered 



1.127 g 



20 



lOU 



* Total solvent soluble acids 



I 



REFERENCES 

Bradley, W.H. , 1966, Tropical lakes, copropel and oil shale. Bull. 
Geol.Soc.Amer. 77» 1333-1337. 

Bradley, W.H. , 1970, Green River oil shale - concept of origin extended. 
Bull.Geol.Soc.Amer. 8l, 985-IOOO. 

Burltngame, A.L. , Haug, P.A. , Schnoes, H.K. and Simoneit , B.R. , 1969a, 
Fatty acids derived from the Green River formation oil shale by 
extractions and oxidations - a review. In: Schenck, P.A. and 
Havenaar, I. (eds.). Advances in Organic Geochemistry 1968, 
pp. 85-129 » Pergamon Press, Oxford. 

Burltngame, A.L. and Simoneit, B.R. , 1968a, Isoprenoid fatty acids 
. isolated from the kerogen matrix of the Green River formation 
(Eocene), Science I60, 531-533. 

Burlingame, A.L. and Simoneit, E.R. , 1968h, Analysis of the mineral 
entrapped fatty acids isolated from the Green River foi-mation. 
Nature 218, 252-256. 

Burlingame, A.L. and Simoneit, B.R. , 1969h, High resolution mass 

spectrometiy of Green River formation kerogen oxidations. Nature 
222, 7UI-7H7. 

Cane, R.F. , I969, Coorongite and the genesis of oil shale. Geochim. 
Cosmochim.Acta 33, 257-265. 

Cardosa, J., Brooks, P., Eglinton, G., Goodfellov, R. , Maxwell, J.R. 
and Philp, R.P. , 1975, Lipids in recently deposited algal mats 
at Mormona, Baja California. This volume. 

Down, A.L. and Himus, G.W. , 197^ » A preliminary study of the constitution 
of kerogen. J. Inst. Pet. 27 > ii26-Uftlt. 

Djuricic, M.V. , Vitorovic, D. , Andresen, B.D. , Hertz, H.S. , Murphy, 

R.C., Preti, G. and Biemann, K. , 1971, Acids obtained by oxidation 
of kerogens of ancient sediments of different geographic origin. 
In: von Gaertner, H.R. andWehner, H. (eds.), Advances in Organic 
Geochemistry 1971, p. 305-321, Pergamon Press, Oxford. 



References ( cont ' d. ) -2- 



Eglintpn, G. , 1973» Chemical Fossils: a combined organic geo chemi caJ. and 
environmental approach. Pure and App. Chem. 3^> 611-632. 

Forsman, J. P. and H\int, J.M. , 1958, Insoluble organic matter (kerogen) 
in sedimentary rocks. Geochim. Cosmochim.Acta 15, lTO-182. 

Golubic, S. , 1973, The relationship between blue-green algae and carbonate 
deposits. In: Carr, N.G. and Whitton, B.A. (eds.). The Biology 
of Blue-Green Algae, p. lt3U-U72, University of California Press, 
Berkeley and Los Angeles. 

Han, J., McCarthy, E.D. , Van Hoeven, W. , Calvin, M. and Bradley, W.H. , 
1968, Organic geochemlcal studies II. A preliminary report on the 
distribution of aliphatic hydrocarbons in algae, in bacteria and 
•in a recent lake sediment. Proc. Hat. Acad. Sci. USA 59, 29-33. 

Hites, R.A. and Biemann, K. , I97O, Computer evaluation of continuously 
scanned mass spectra of gas chromatographic affluents. Anal. Chem. 
U2, 855-860. 

Jones, C.L. , 1922, The problems of the shale oil industry. Chem.Met. 
Eng. 26, 5ij6-553. 

Lawlor, D.L. , Fester, J.I. , and Robinson, ¥.E. , I963, Pyrite^ removal 
from oil shale concentrates using lithium aluminium hydride. 
Fuel 1*2, 239-2ltlt. 

Logan, B.¥. , Rezak, R. and Ginsburg, R.N. , I96U, Classification and 
environmental significance of algal stromatolites. J.Geol. 72, 
68-83. 

Oehler, J.H. , Aizenshtat, Z. and Schopf, J.W. , 197hy Thermal alteration 
of blue-green algae and blue-green algal chlorophyll. Am. Assoc. 
Petroleum Geologists Bull. 58, 12l|-132. 

Robinson, W.E. , Cummins, J.J. and Stanfield, K.E. , I956, Constitution 

of organic acids prepared from Colorado oil shale based on n-butyl 
esters. Ind.Eng.Chem. U8, 113^-1138. 

Robinson, W.E. , Heady, H.H. and Hubbard, A.B. , 1953, Alkaline permanganate 
oxidation of oil-shale kerogen. Ind.Eng.Chem. it5, 788-791. 



References (cont'd.) -3- 



Robinson, W.E.' and Lawlor, D»L. , 196I, Constitution of hydrocarbon-like 
■materials derived from kerogen oxidation products. Fuel 1(0, 375-388. 

Robinson, W.E. , Lawlor, D.L. , Cummins, J.J. and Fester, J.I. , I963, 

Oxidation of Colorado oil shale. Biireau of Mines, Rept. of Invest. 
6166, 33 pp. 

Sackett, VT.M. , Poag, C.W. and Eadie, B. J. , 197^, Kerogen recycling in 
the Ross Sea, Antarctica, Science I85, IOU5-IOU7. 

Schopf, J.W. and Barghoorn, E.S., I967, Alga-like fossils from the 
esirly precambrian of South Africa. Science 156, 508~512. 

Simoneit, B.R. and Burlingame, A.L. , 1973, Carboxylic acids derived 
from Tasmanian tasmanite by extractions and kerogen oxidations. 
Geochim.Cosmochim.Acta 37, 595-610. 

Thome, H.M. , Standfield, K.E. , Dinneen, G.U. and Murphy, W.X. , I96U, 
Oil Shale technology: A review. Information Circular 82l6 U.S. 
Bureau of Mines, Washington. 

VondeerHaar, S.P. , 1973, Evaporite environment at Laguna Mormona, Pacific 
coast of Baja California, Mexico. Geol.Soc.Amer.Abs. -with Programs 
5, 117-118. 



3^' 



The Costs of Efficiency 

Implications of Educational Technology* 




IDA R. H O O S 



This paper traces the impacts of technology on 
education and illustrates the steady progression, always rationalized by 
the ethos of efficiency, from teacher aids to computer-aided instruction, 
from data-processes to facilitate record-keeping to omnivorous 
management information systems. The point is made that at present a 
management syndrome pervades education planning at all levels. This 
has created an environment hospitable to the family of techniques re- 
lated to systems analysis, with its companions and components, cost/ 
benefit measures, program budgeting. Quantitative concepts such as 
productivity, performance, and accountability have rendered the notion 
of academic excellence virtually obsolete. After a review of the current 
state-of-the art, the paper finds that industry-style efficiency may be 
more costly than beneficial to education. 

Education, to an extent greater, perhaps, than any other societal in- 
stitution, has been vulnerable to invasion, if not takeover, by 
"technology," in its myriad manifestations. Reason for this suscepti- 
bility is readily apparent. Forever entangled in the mesh of causality 



'Editor's note: The Journal periodically will publish an article which in its broad focus on the 
institution of education also addresses those with postsecondary interests. This paper is presented 
as having such an orientation. 

Ida R. Hoos is a research sociologist at the Space Sciences Laboratory, 
University of California, Berkeley. 



JHE, Vol. XLVI. No. 2, March/ April, 1975 / 141 



JOURNAL OF HIGHER EDUCATION 

that makes it at one and the same time creator, curator, reflector, and 
transmitter of the values of the society, education is perforce in 
constant flux. For this seeming instability it is always open to criticism 
for not being responsive or relevant, both of which are almost unat- 
tainable, especially during periods of social upheaval. Moreover, the 
high visibility of its processes and products render education a likely 
target for the axe-wielding of every^litician from county to Congress 
and for axe-grinding by psychologists, sociologists, economists, and 
many others possessed of a zeal to reform or "innovate." Always a 
proper outlet for the "community participation" impulse, education is 
bossed by school boards made up of businessmen, bufieted by 
frustrated fringe activists from various arenas, and used as a stepping- 
stone by politicians, more thirsty for advancement of their own per- 
sonal power than for that of public knowledge. 

Echoing the tenor of the times, education has abandoned the person- 
nel practices that made teaching a catchall for spinsters and sissies, 
that arbitrarily created "counselors" out of teachers who could not 
cope in the classroom, and that perversely rewarded competence by 
transferring it from classroom to administration. The organization of 
teachers into strong unions, mobilization of women into egalitarian 
movements, and a new set of social mores have brought about fun- 
damental changes, too numerous to recount and too obvious to review 
here. What can be pointed out is that concomitantly goals for and ex- 
pectations from education have undergone transformation. 

In the early days of public education in the United States, the prime 
objective was inculcation of the virtues of self-control and self-dis- 
cipline. To preserve and promote the social order were considered 
proper activities for the school.' Industrialization and immigration in 
the latter part of the nineteenth century shifted emphasis to the "esca- 
lator" potential of education. Representing an avenue for upward mo- 
bility, education became synonymous with opportunity, a stereotype 
that has evinced remarkable resiliency in the face of repeated attacks 
over the past 3S years. Changing expectations have caused shifts to, 
away from, and back again toward vocational education, all within the 
span of two generations. The revival of prayer and religion in the 
schools suggests a return to the good old fundamentalist values of yore. 
Darwin has been banished from science courses; there is nostalgic 
yearning for the teaching of morality. 



'R. J. Wiebe, "The Social Functions of Public Education," American Quarterly, 21 (Summer, 
1969), 147-64. 



142 



i 1^ 



COSTS OF EFFICIENCY ir 

With education at once a reflection of and a response to the pre- 
vailing societal codes, certain adaptations of the current ethos of 
efficiency were bound to occur. The proposition being that teachers are 
overworked, and the corollary, that any device or procedure that can be 
called a teachers' aid is beneficial, instant rationalization and 
justification have been on tap for a succession of linked phenomena that 
began with the introduction of "objective tests," includes the multi- 
farious uses of computers for reporting, teaching, and management, 
and brings to education the space age concepts and tools popularly 
called systems analysis, which encompasses cost/benefit analysis, 
program budgeting, performance evaluation, and even Delphian predic- 
tion. 



EFFICIENCY THROUGH TECHNOLOGY 

Long before automation in the more tangible and expensive form of 
electronic data-processing entered the schools, efficiency manifested it- 
self in the form of self-administered, true-false, or multiple-choice 
("cafeteria") tests. Because they were machine-processable, they 
qualified as teachers' aids and soon became the basis for all mass- 
grading efforts. The College Entrance Examination Board abandoned 
essay-type questions in favor of SATs (Scholastic Aptitude Tests), 
grading of which is totally automated. The student's total capacity to 
communicate via the written word was couched in the one short 
biographical essay so fraught with life-or-death importance as to 
paralyze the most talented. Qualifying examinations for graduate work 
(Graduate Record Examination Tests) are of the same type as are also 
those intended for specialized curricula such as medicine and law. 
These instruments, designed to screen applicants with dispatch, have 
satisfied the criterion of speed and thus fulfilled the expectation of 
efficiency but not without costs. We now are beginning to perceive that 
standardized tests, devised primarily as an aid to convenient 
classification by teachers, deans, and administrators, have exerted a 
feedback effect on course content and curriculum planning. Many edu- 
cators recognize the inadequacy of this type of testing as an index to 
scholastic ability; students with the greatest intellectual promise being 
at a particular disadvantage with the limited, mechanical format.' As 



'Ida R. Hoos, Systems Analysis in Public Policy (Berkeley, Calif.: University of California 
Press, 1973), pp. 162 flr. 



143 



.wi;a'im^ii:«>i*i> 



JOV/RNAL OF HIGHER EDUCATION 

we begin to assess costs, we realize that the devil-take-the-hindmost 
calculus that valued the shortcut neglected deep-seated consequences. 
The bargain was, indeed, Faustian. 

With the art of communication reduced to making check-marks, 
Johnny cannot write. He gets through grade and high school without 
having learned to articulate his thoughts on paper. If he enters college, 
"bonehead English" cannot remedy the accumulated deficiency created 
by 1 2 years of neglect. Throughout his college career, his inability to ex- 
press himself in writing is a handicap. Students, even Ph.D. candidates, 
have been known to freeze into a kind of numbness at the stage of 
dissertation writing. As any personnel officer or teacher in adult 
education classes can attest, the Johnnies and Janes who have to fill out 
as much as a one-sentence item on an application form are struck with 
a kind of petrification. They simply cannot write and hence resort to the 
most desperate face-saving. The incidence of lost or broken reading- 
glasses is impressive; the transparence of the pretext to carry the form 
home, pathetic. In occupations such as police work, where rq)ort- 
writing is crucial, this lack of ability can cause serious internal opera- 
tional problems. 

Before the advent of the computer, the report card served as a com- 
munication link between school and home. Parents were required to 
sign it, and the "Remarks" column invited dialogue, if only a fairly 
superficial sharing of observations, about the child. At semester's end, 
the card represented an interesting cumulative summary. No perfunc- 
tory matter, this, for the report card was the high point in the term. 
The IBM machined printout has changed all this. Like a beer can, the 
card is now one-way and disposable. Teachers' comments in coded 
form convey ambiguity, the numeral S meaning "assignments not 
turned in and/or properly prepared," and 8, "misconduct and/or poor 
attitude." Response from parents is neither invited nor expected; the 
system simply cannot accommodate them. Paradoxically, while pupil- 
processing efficiency increases, school administrators hire consultants 
to help them overcome alienation and apathy. Encounter groups and 
public relations gimmicks, such as "Open House Night," "Black His- 
tory Week," and "Ecology Week," are supposed to enliven parental in- 
terest, often deadened beyond recall. 

Thanks to "flexible classroom scheduling," a computer program de- 
veloped by Stanford Research Institute and used widely in the United 
States and Japan, the few options allowed high school seniors for 
honors performance have been withdrawn. Where previously the 



144 



COSTS OF EFFICIENCY 

Students were privileged to select a particular teacher or aspect of 
English as reward for earlier endeavor, now the system makes any such 
deviation prohibitively expensive. The same schools that buy such pro- 
grams in the name of efficiency alienate, and thus effectively dampen 
enthusiasm, but expend time and resources on workshops solemnly 
devoted to motivation. Teachers and counselors, under pressure to de- 
liver to the system the information it constantly demands and in the 
form it requires, complain that they have little time for personal 
contact with the students. Suggested as a remedy are group counseling 
sessions, utilizing closed-circuit television, or computer programs set to 
conduct counseling interviews.^ In the later years of the lives of these 
students, when "relating" becomes a yearning necessity, ersatz 
primary groups are formed, with political ideology, religion, sex, or 
economy variously serving as the basis for association. Sometimes the 
course taken is one of total rejection— of dropping out. All the while, 
the analysts seriously ponder anomie and alienation in journal articles 
and at annual conferences in Vienna. 



TECHNOLOGY AS NOSTRUM 

Always the public whipping boy, education has been accused by "ex- 
perts" of harboring a 30-year lag between "innovation and widespread 
adoption of the innovation." A Congressional report quotes an in- 
dustrialist who happens also to be a school board president as saying, 
"the aircraft industry would go out of business in two years if it 
changed as slowly as education."^ Not only is this statement presump- 
tuous nonsense, but the implied ascription to it of authoritativeness 
downright sophomoric. To begin with, "innovativencss," the "buzz" 
word since the early sixties, does not stand as an unchallenged p/uj. Al- 
though the status quo may not represent the epitome of perfection, 
there is nothing intrinsically good about change. Innovation, under 
certain circumstances, can cause havoc. In the second place, the air- 
craft industry is an unfortunate selection as model in that (1) it feeds 
sumptuously at the public trough from R & D to operating subsidy. 



'Harry F. Silberman, "Applications of Computers in Education," paper presented at the 
American Management Association Conference, New York, August 9, 1967, System De- 
velopment Corporation SP-2909/OOO/OI, Santa Monica, California, p. 8. 

'"Automation and Technology in Education," a Report of the Subcommittee on Economic 
Progress of the Joint Economic Committee. Congress of the United States, 89th Congress, 
Second Session. August 1966, p. 3. 



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JOURNAL OF HIGHER EDUCATION 

and (2) its profligate mismanagerial practices are shielded from view by 
the hanky panky that accompanies high-level transfers of allegiance in 
the game of musical chairs played by retired "brass," government 
bigwigs, and corporate potentates. Education does not enjoy the 
comfort of knowing that its failures will be rewarded by prompt 
Congressional appropriations. Education, always maligned, must write 
a success story. And, using crocodile tears of sympathy as leverage, 
technologists make the most of the need to create a favorable image 
and such occasions as Congressional hearings to promulgate thdr 
wares. 

For example, in the Report put out, significantly, by the Joint Eco- 
nomic Committee and not the Education Committee, commiseration 
pours forth over the orders of magnitude by which "the amount of 
knowledge to be communicated during the process of education" is in- 
creasing. Stupefying statistics are paraded: 

There have been estimates that as much technical knowle(^e will be de- 
veloped in the next 30 years as has been accumulated in the entire past 
history of mankind. In this country alone, we produce approximately 
2S,000 technical papers every week, along with 400 books and 3,500 arti- 
cles." 

Then follows the predictable polemic: "Facing such prospective re- 
quirements, our educational system is threatened by a decline in 
relative effectiveness unless improved productivity can be brought to its 
aid." Emphasis is here added to some of the foregoing phrases to call 
attention to the classic elements of the sales campaign being mounted. 
The sly equating of the current information explosion with knowledge, 
the onus of ingesting this superabundance, subtly assigned to the educa- 
tional system, "effectiveness" and "improved productivity" slipped in 
as terms generally accepted and clearly understood — all of these 
serve as preamble to the "pitch." 

The solution put forward is, of course, technological aids to 
education. And these are listed to include "educational television, both 
open and closed; video tape; computerized instruction; the use of com- 
puters for student testing, guidance, and evaluation, and the storage, 
retrieval, and distribution of information; programmed courses of 
instruction, teaching machines, particularly the 'talking typewriter*; 
the use of microfilm and microfilm viewing equipment; and language 
laboratories." Many of these items, presented as assets, actually exem- 

Mbid..p.4. 



146 



^-! 



COSTS OF EFFICIENCY 

plify egregious costs of efficiency, as will be noted later in this paper as 
preparation for the discussion with which we will mainly be con- 
cerned — that of systems analytic techniques and their effects on 
education. As we have seen in the remarks cited above, there is a 
definite progression in the forensic; it moves seductively from 
technological aids for teachers to techniques that mold the very 
philosophy of education. The systems approach, represented to the 
Congressional committee as "the creative combination of a variety of 
skills and devices to produce desired results, an approach that is 
proving highly successful in the military sphere," becomes the pre- 
vailing paradigm, the way education will be conceived, contrived, and 
executed." 



COMPUTER-AIDED INSTRUCTION 

Computer-aided instruction has its roots in programmed instruction, 
a 1950 phenomenon which received considerable impetus from the 
work of Skinner, the latter-day developer of behaviorism and the ex- 
ploiter of all its associated principles once, but not for all, in deep disre- 
pute.^ By 1968, several thousand students ranging from elementary 
school to university level had received a significant portion of their 
instruction in at least one subject area under computer control. In 
projects developed at Stanford University under a grant from the Car- 
negie Foundation and, later, Title IV funds, elementary school children 
designated as "culturally disadvantaged," were brought by bus to 
receive instruction from a program in initial reading and mathematics. 
It works this way: 

The first thing the student does is peck out his name on the typewriter. 
The computer then searches its memory to determine what the student 
did on his last lesson and what his lesson should be this time. If it is a 
reading drill, for example, the computer may display a word on the 
screen at the same time a recorded voice pronounces the word in the 
earphones. After several words are simultaneously displayed and 
pronounced, they are displayed on the screen and the recorded voice asks 
the student to pick out one. This can be done either on the typewriter or 
with the light pen. If the student selects the right answer, the recorded 
voice in his earphone says, "Yes, that's correct."* 



•Ibid., p. 5. 

'B. F. Skinner, The Technology of Teaching (Nev/ York: Appleton-Ccntury-Crofts, 1968). 
■John Rhea, "1968 Seen Critical for Computer Education," Aerospace Technology, (January, 
1968), p. 20. 



147 



JOURNAL OF HIGHER EDUCATION 

Dollar costs of the Stanford, and all systems, which involve capital 
investment in hardware, are high. The addition of sophisticated audio 
and graphic components increases costs substantially, with greatly ac- 
celerated utilization the only likely means to reduction of cost-per- 
student-hour. It is on the assumption of a tremendous growth in com- 
puterized education that the designers of the Stanford system, which 
has been replicated, emulated, and expanded elsewhere, with generous 
federal and foundation funding, confidently calculate lowering of future 
per unit costs as compared to that associated with the "approximately 
3,000 students . . . processed daily" in the Stanford project.* Not at all 
surprising, the same architects of this pupil processing project deplored 
the absence of concrete measures of efficiency. In a wishful projection 
of their assembly-line notion of education, they urged a definition of 
"some standard unit, some 'erg' of learning and forgetting.'"" 

The current preoccupation among experts in educational technology 
as to the distinctions between and relative merits of "computer-aided" 
and "computer-managed" instruction serves only to obscure the basic 
issues, not to eliminate them. Technical in emphasis and advocative in 
conclusion, the debate ignores the possibility that this substitution of a 
"learning facilitator" for a real-life teacher" and the notion of "be- 
havioral engineering," with attendant concepts, such as "stimulus con- 
trol" and "contingency management,"" violate basic psychological 
principles of learning, as exemplified in an experiment conducted by 
Gordon W. AUport some years ago." In it, 250 college students were 
asked to write down three vivid memories of their eighth grade school 
work and to indicate the kind and degree of their active participation. 
Were they reciting, performing, arguing, talking? Or were they listening 
or watching without overt involvement? Allport found that three- 
quarters of the responses recalled situations in which the subject 
himself was actively participating. This experiment, corroborated in 
real-life experience, has been repeated many times. 

As for the "culturally deprived children," who are the prime targets 
for hard sales campaigns for educational technology, a socially 



•R. C. Atkinson and H. A. Wilson, "Computer-Assisted Instruction," Science, (October, 
1968), p. 73. 

"Ibid., p. 76. 

"Perry E. Rosove, "Toward Education in Real Time," paper prepared for session on "Real 
Life Information Systems and the Public Interest," presented at Fall Joint Computer Conference, 
San Francisco, Calif., Dec. 9-11, 1968, SP>3140, Santa Monica, Calif. System Development Cor- 
poration, August 7, 1968, p. 20. 

"Harvey J. Brudner, "Computer-Managed Instruction," Science. 162 (1968), 962-76. 

"Gordon W. Allport, Personality and Social Encounter (Boston: Beacon Press, I960) p. 185. 



148 



COSTS OF EFFICIENCY 

isolated, dehumanized learning environment is possibly the worst kind 
of approach to their special needs. It may be that a very significant 
factor in their deprivation is the predominant role played by an 
electronic box in their lives. Baby-sitter, beguiler, educator, 
supersalesman, mentor, television, with its one-way stimulus, has so 
conditioned them that they consider education all play and no work. 
Taught only to expect a kind of entertainment and deprived of the 
stimulation that comes into the learning situation from interaction with 
teacher and with other students, the "culturally deprived" pupils reach 
high school not only unable, but not interested in learning how, to read. 
Instant relevance must be provided in special courses at the college 
level in order to retain them and thus preserve the facade of "equal op- 
portunity," "affirmative action," or whatever seems to have "retention 
value" for all students and constitutes open sesame to federal funding. 
Thus, the University of Maine offers a course in wine-tasting, a Florida 
college gives credit to "film going"; at the University of California a 
class, Forms of Folklore, Anthropology 1S9, collects and analyzes lim- 
ericks, graffitti, dirty and ethnic jokes, myths, and legends. Students 
were asked why the class was so popular. One girl, who admitted 
signing up because the scheduling was convenient and the five credits 
useful, replied, "It's interesting. We do more laughing than anything 
else." Another student was glad he got into the class because "I dig 
telling jokes, and I might be able to pick up some new ones from him 
(the professor)."'* 

Computerized education has been criticized by psychologists for 
taking into account only a small segment of the learning environment 
and thus skewing the process in ways that are ultimately destructive. 
Criticism has also been raised on social grounds, the contention being 
that "noneducation experts" are dominating the field. The aggressive 
invasion by hardware merchants, software dealers, engineers, opera- 
tions researchers, systems analysts, and the like portend a total and 
self-perpetuating technological takeover. The possibility has been men- 
tioned that the $SO-billion-a-year education market, which Xerox, 
RCA, General Learning Corporation, Raytheon, Lockheed, and others 
are vigorously exploiting, could lead to an "education-industrial com- 
plex," in which large corporations would determine what should be 
taught. As yet unmentioned is the obvious link between programmed 
instruction and propaganda, although apparently the White House 
Office of Telecommunications Policy has already found "potential 

""Jokes, Myths, Fill Folklore Class," The DaUy California. Februarys, 1974. 



149 



JOURNAL OF HIGHER EDUCATION 

abuse" in the use of audio-visual materials, in that public service 
messages could become vehicles for "thought implantation."'* Skinner 
and his followers having already reduced education to a low form of 
conditioning, the likelihood of determined brainwashing is not at all far- 
fetched.'* 



SYSTEMS TECHNIQUES AS APPLIED TO EDUCATION 

To belabor the point that education at all levels from local to federal 
is mismanaged is tantamount to the reverse of an attack on 
motherhood. Everyone can and does criticize education, its shortcom- 
ings, and failures. And, no doubt, with as much, and probably more, 
reason than to censure other public institutions. Heir to personnel 
practices that put basketball coaches into administrative position just 
because those jobs were reserved almost exclusively for males, caught 
on the pendulum that swings from the classical to the vocational, from 
the scholarly to the relevant, buffeted by the forces of social change 
that cast the schools as prime instrument of ethnic, class, and cultural 
integration, assailed by ideologues and idealists, pragmatists and 
politicians, parents and professionals, education provides a slow- 
moving target vulnerable and undefensible. 

That systems analysis and all its attendant quantified techniques 
touted to improve managerial efficiency should emerge as a promising 
panacea ubiquitously applied seems only logical. The systems approach 
has appeal, especially in its philosophic guise of "viewing a problem or 
situation in its entirety with all its ramifications, with all its interior 
interactions, with all its exterior connections and with full cognizance of 
its place in its context."'^ Systems analysis is, however, not a merely 
philosophic notion but an operational actuality. In fact, it is used inter- 
changeably with operations analysis and, as such, refers to a specific 
technique that consists of constructing a mathematical model of an 
operation. This model is a set of equations which presumably will allow 
one to calculate changes in the outputs of an operation when specified 
inputs have been changed, the purpose being to optimize some aspect of 



'*Les Brown, "Audio- Visual Spending by U.S. cited as 'Potential For Abuse,'" The New York 
Times, February 12, 1974. 

'•B. F. Skinner, Beyond Freedom and Dignity (New York: Alfred A. Knopf, 197 1 ). 

"Alexander M. Mood, "On Some Basic Steps in the Application of System* Analysis to 
Imttuclxon," Socio- Economic Planning Science. 1 (1967), pp. 19-26. 



150 






COSTS OF EFFICIENCY 

the outputs. The systems analysis does not attempt to be complete in 
its mathematical model, but rather "to be judiciously selective by in- 
cluding significant factors and omitting or aggregating minor factors in 
order to keep the model to manageable proportions for purposes of the 
optimization."'* This statement, so guilelessly descriptive, contains the 
very hidden agenda that undermine the credibility of these techniques as 
"scientific," "objective," and "rational." "To be judiciously selective" 
is to impose a judgment, which reflects the Weltanschauung of the 
analyst. The distinction between "significant" and "minor" factors is 
an expression of preference, bias, and, possibly, ignorance. "To keep 
the model to manageable proportions" discloses the current disease, 
once called "modelitis" by Kahn; preoccupation with the model often 
causes neglect of the real-life situation. 

History and happenstance have encouraged the wide and ever-in- 
creasing use of the techniques. Ours being the Technological Era, the 
Space Age, the systems approach has become the "dominant para- 
digm,"" of our time and, as such, is being applied to every facet of our 
lives — health, welfare, transportation design, land use, education, and 
even the future of society. Moreover, systems analysis epitomizes the 
Space Age. When the overworked clich£, "A nation that can put a man 
on the moon" is evoked as evidence of technical prowess, reference is 
being made to the systems methods used with such singular success in 
space exploration. 

Another pillar of prestige stems from the World War II experience 
when, under the name of Operations Research, the techniques were 
credited with having won the Battle of Britain. Secretary of Defense 
Robert S. McNamara, with his Rand associates, added a dazzling 
chapter to the saga of systems analysis. That the wizardry was short- 
lived, that subsequent disclosures by Congressional committees found 
the systems approach to be directly responsible for cost-overruns, for 
unconscionable padding, and other fiscal abuses have been cavalierly 
ignored. The apotheosis accomplished, only reverence remains; the high 
priests, who could have elected to keep the emperor honestly naked, se- 
lected the path of least resistance and greatest personal return. 
Deserting the DOD for high places in civilian agencies of government, 
they perpetuated the mythology in unwonted places, with the result 

'•Ibid., p. 19. 

"T. S. Kuhn, The Structure of Scientific Revolution (Chicago: University of Chicago Press, 
Third Impression, 1971). Kuhn calls the dominant paradigm a fundamental way of perceiving, 
thinking, and doing, consistent with a particular vision of reality. 



ISl 



JOURNAL OF HIGHER EDUCATION 

that program budgeting (PPB)*" became the iron law of administrative 
accounting; favorable cost/benefit ratios became the way to financial 
security; data, data-gathering, and information systems became an 
official obsession; and production and performance evaluation became 
the great national numbers game. 

The literature on systems analysis in education burgeons with every 
conference on cost/effectiveness, with every symposium on managerial 
efficiency. "Experts," arising from economics, econometrics, opera- 
tions research, engineering, sociology, education, and even philosophy 
are indistinguishable as to orientation. Quite contrary to early expecta- 
tions that the systems approach would encourage multidisciplinary 
participation and creative synergism, experience reveals that almost ir- 
respective of specialized input, the product comes out the same, a kind 
of amalgam in which any methodological rigor that had previously 
existed has been obliterated. Noteworthy here is the fact that a kind of 
law emerges, viz., the softer the discipline, the more amenable it is to 
the technological takeover. As might be expected as corollary to this, 
standards for expertness are practically nonexistent and accrue more 
to institutions than to individuals. Thus, persons who profess expert- 
ness in the management of solid waste systems claim without hesitation 
or qualification "systems competence" in education systems manage- 
ment and the Rand imprimatur virtually assures a favorable reception. 

The weakness of relying on semantic similarity to transfer the tech- 
niques from the military and aerospace effort to social planning and 
education in particular has been discussed elsewhere." The requisites 
for proper application of systems analysis have been specified but never 
satisfied." This is not necessarily due to ignorance. Besides the caveats 



"Program budgeting has been described as "a way of organizing cost data in such a manner 
that they can be used to analyze different courses of action in terms of cost and utility" (Lawrence 
Bogard, "Management in Institutions of Higher Learning," in Papers on Efficiency in the 
Management of Higher Education, by Alexander M. Mood, Cohn Bell, Helen Brownlee, 
Lawrence Bogard, and Joseph McCloskey (Berkeley, Calif.: The Carnegie Commission on Higher 
Education, 1972), p. 29. 

"Ida R. Hoos, Systems Andysis in Public Policy (Berkeley, Calif.: University of California 
Press, 1973). 

John S. Gilmore, John J. Regan, and William S. Gould, Defense Systems Resources in the 
Civil Sector, prepared for the U.S. Arms Control and Disarmament Agency (Washington, D.C.: 
U.S. Government Printing Office, 1967). 

Anthony G. Oettinger and Sema Marks, "Educational'Technology: New Myths and Old 
Realities." Harvard Education Review. 38 (Fall. 1968). p. 9. 

"Robert Boguslaw, The New Utopians (Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1965). 

A. M. Mood, "Cost-Benefit Analysis of Education," in Analysis for Planning, Programming, 
Budgeting, Mark Alfandary-Alexander (Ed.) (Potomac, Maryland: Washington Operations Re- 
search Council, 1968), pp. 17-26. 



152 



COSTS OF EFFICIENCY 

couched virtuously in footnotes in the plethora of papers offering input- 
output models, cost/effectiveness schema, and other mathematical 
exercises, there are forthright and professionally competent 
criticism s.'^ But the voices of reason are still and small compared 
with the clamor for "rationality," as paraded in the cloak of the tech- 
niques that will bring the "contributions from management science, 
operations research, organizational theory, and economics ... to help 
solve administrative problems which typically confront colleges and 
universities" and, one might add, all other levels of education.'* Mood 
has suggested that the first problem to be faced is whether the question 
to be studied is suitable for a system analysis.'* Apparently, the new 
breed of "education managers" does not agree. Everything having to do 
with the educational process, from programs and policy at the topmost 
level to introducing a foreign language in the second grade in Chule 
Vista, California, is fitted into this Procrustean bed. Education plan- 
ning has been forced into the same mold that was precast for getting 
the "biggest bang for the buck" (cost-effectiveness calculation in the 
Department of Defense) and manure-disposal in Manteca (Systems 
Analysis of Urban and Rural Waste, Aerojet General Corporation, 
1968). 

How does the "education manager" approach his task? Primarily, he 
is an information-gatherer. He is a model-builder. He "optimizes." 
Cognizant of financial stringency everywhere, he reasons that 
"improvement of operating efficiency" is the solution. "Efficiency," he 
says, "is measured as a ratio between two variables: cost and output."'* 



"As exemplilied in writings by Guy Beneviste, "The Role of Utopian Models in 
Socioclectronics," invited paper. Research Committee on Sonotechnics, International Socio- 
logical Association, Loughborough, England, November 16-18, 1973: "Consequences of 
Excessive Educational Planning," paper presented at International Society of Educational Plan- 
ners, "Science and Man in the Americas," American Association for the Advancement of 
Science, Mexico, June 25-30, 1973. 

Paul Alper, "A Critical Appraisal of the Application ofSystemt Analysis to Educational Plan- 
ning Models," IEEE Transactions on Education, E- 1 1 (June, 1968), pp. 94-98. 

P. E. Balderston, "Thinking about the Outputs of Higher Education," Paper P-S (Berkeley, 
Calif.: Ford Foundation Program for Research in University Administration, May 1970). 

Earl Cheit, "The Systems Challenge— How to be Academic though Systematic," paper de- 
livered at annual meeting, American Council on Education, Washington, D.C., October 10, 1973. 
To be published in the Annual Proceedings. 

"Paul W. Hamelman (Ed.), Managing the University: A Systems Approach (New York: 
Praeger Publishers, 1972). 

"A.M. Mood, "Cost-Benefit Analysis of Education," in Analysis for Planning, Programming, 
Budgeting, Mark Alfandary-Alexander (Ed.), (Potomac Maryland: Washington Operations Re- 
search Council, 1968), p. 20. 

"Howard R. Bowen and Gordon K. Douglass, Efficiency in Liberal Education, Carnegie Com- 
mission on Higher Education (McGraw-Hill Book Company, 197 1 ). p. 3. 



153 



JOURNAL OF HIGHER EDUCATION 

An increase in efficiency occurs, therefore, when output increases while 
cost remains constant. Education thus becomes a factory model — 
input-processor-output. University Hall, U.S.A., is busily at work 
generating management information systems, constructing models, 
and conducting cost/benefit comparisons in order to accomplish 
"analytic suboptimization," if nothing else. 

These three activities merit scrutiny. The management information 
system (MIS) in higher education is 

a configuration of men. machines and methods whidi supports manage- 
ment in the collection, storage, processing, and transmission of in- 
formation for operation, control, evaluation, and planning of a 
university. Seen in this way, the MIS draws upon the operating systems 
and supports both the PPB system and the administrative management 

and control system of the institution In an MIS recently designed 

for a state university the regular outputs to top administrators consist of 
47 reports. Of these, 20 are planning reports and 27 concern control and 
evaluation of operations. The reports in their entirety cover the academic 
program students, faculty, support sciences, facilities, and finances.*' 

The generally conceded need for information has rationalized the 
most expensive, cumbersome, and demanding systems which, when tied 
into a computer, add confusion and complication while they consume 
precious resources. All the while that the information system is 
performing its sorceror's apprenticeship, simple bookkeeping opera- 
tions are in disarray. At the University of California, for example, vital 
procedures, such as personnel and accounting, are almost hopeless bot- 

{ tlenecks, and the very information essential for proper model-building 

is nonexistent. The student-flow model is a case in point. Apparently, 
the objective here is to ascertain the "retention rate," itself a matter of 

I dubious worth. Gathered for this purpose are figures on admissions, 

enrollments, and withdrawals. But when all is said and done, no one is 
the wiser, because no distinction has been made between students who 
drop out from the University of California to join the "drug culture" 
and those who transfer to Princeton; those who forsake formal 
education permanently and those who withdraw for a short period, 
perhaps even to carry on related field work. New and re-enrollments 
are undiflerentiated, with the result that "retention rate" is calculated 
[ on an erroneous base, a hodge podge of duplication and double count. 



"Charles A. Nelson, "Observations on the Scope of Higher Education Planning in the United 
States," Chapter 4 in Managing the University: A Systems Approach, Carnegie Commission on 
Higher Education (McGraw-Hill Book Company, 1971), pp. 36 and 37. 



154 



COSTS OF EFFICIENCY |i 

Forgotten in the frenetic numbers chase is the possibility that "reten- 
tion rate" is not, in itself, cost/effective! It just may not be worth all the 
bother. Especially when considered in conjunction with the "relevant" 
curricula crafted to keep reluctant students in college, a high retention 
rate seems to be monumentally irrelevant to education. 

The University of California '"faculty flow model" has as inputs 
"economic" and "social" characteristics of the professorial staflf. By 
whose judgment the latter are defined and by what reason the former 
are to be construed as the University's business are not clear. Since 
operation of the model is expected to yield "optimal hiring strategy," 
we can only conjecture about the analyst's criteria for "optimality."" 
What are his "significant social characteristics" — race, color, political 
affiliation, activism in causes? How will they be used in "plotting 
optimal hiring strategy?" Already, some of the effects of the 
University's planning-by-numbers are evident. Instead of valuing its 
older faculty members for the knowledge and wisdom that age pre- 
sumably should have brought them, the University has been waging a 
vigorous campaign to encourage early retirement, so as "to provide 
planned opportunity for flexibility and continuing faculty renewal."** 
"Flexibility" could mean replacing senior faculty by temporary appoin- 
tees; "faculty renewal" could deny tenure. Some optimum faculty 
workload model has dictated the elimination of half of the sabbatical 
leave program at the State Universities (San Francisco, San Jose, Hay- 
ward, et al.) and, by imposing restrictions on the nine campuses of the 
University of California, has had the effect of increasing the faculty's 
work load up to as much as one year in seven. The calculations have 
subtly demeaned the scholarly pursuits of professors, devalued the 
benefits accruing from the sabbatical programs, and given credence to 
figures which reflect inadequately and inaccurately how professors use 
their time. 

Carrying further the "factory" syndrome, an optimum class 
scheduling model aims for more intensive "plant usage." Cost 
considerations and plant utilization, for example, influenced the de- 
cision to institute a quarterly, four-term calendar, possibly an eco- 
nomic success by some calculus, but, after four years of operation, still 
far from unequivocal as to who pays the costs and who derives the 
benefits. The possibility that compacting courses into 10-week sessions 

"John Keller, "New Frontiers in Educational Program Planning and Budgeting and in Educa- 
tional Cost/ Benefit Analysis," speech at symposium at Berkeley, California, January 1 5, 1968. 

""The University Academic Plan, 1974-1978," draft released by Executive Vice President 
Chester O. McCorkle, October, 1973. 

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JOURNAL OF HIGHER EDUCATION 

or, as is now contemplated, scheduling evening classes might interfere 
with employment or other activities of the student's life or adversely 
affect the teaching-learning process does not appear in any model, nor 
do classrooms with standing-room-oiily conditions while a 900-seat au- 
ditorium remains unused, because "all those empty seats would have 
affected the utilization ratio that the state calculates for classroom 
usage."" 

The "favorable ratio" phenomenon is not unique to the University of 
California, discussed here because this institution is typical and idso 
somewhat in the vanguard as to utilization of these "managerial con- 
cepts." Not unexpectedly, the imposition of the techniques has moved 
far out of fiscal affairs and into matters academic. "Plant utilization" 
controls course offerings; "efficiency studies" determine the fate of de- 
partments; "performance" and "productivity" are serious criteria for 
evaluation. When, as now seems to be the case, number of degrees 
awarded is a basis for fund allocation, an interesting feedback effect be- 
comes obvious. By easing its requirements and lowering its standards, a 
department could improve its financial position even though, at the 
same time, it could run the risk of losing its accreditation! As for the 
students, caught in the speed-up processing by the "knowledge fac- 
tory," they will emerge from the output side of the model with de- 
liberately devalued paper that is called a diploma or a degree. 

Performance has become so pervasive a criterion that at the college 
level professors are being rated on this basis. Criteria are, of course, 
scanty and slippery, for beyond number of hours of teaching and 
number of journal articles written, there are only the elusive qualitative 
factors. Recommendations by an ad hoc review committee at Berkeley 
point up the new trend — evaluations of professors* performance by 
students. Besides constituting an abdication of the responsibility of 
maintaining academic excellence through properly authorized pro- 
fessional channels, this kind of procedure allows for the most flagrant 
abuse, no distinction being made between the rating by those who 
earned A's and those who failed the course. If professors are forced to 
pander to popular preferences in order to survive, we may yet see a paid 
claque performing in the classroom! 

At the elementary and secondary school levels, emphasis on "perfor- 
mance" and "productivity" have taken on somewhat different, but 
nonetheless portentous, manifestations and implications. Ac- 



"Statement of Jean Dobrzensky, of Chancellor's Office, University of California, at quoted in 
DaUyCalifornian. January 24, 1974. 



156 



COSTS OF EFFICIENCY 

companying the predilection to apply performance measures to school 
programs is the necessity to cast pupils in the role of producers whose 
"output" represents the basis for calculation of cost/effectiveness 
ratios. Even though PPBS as such is no longer obligatory, its official 
demise occurred after the point of no return had been passed. Its ves- 
tigial remains hang on under new names, and administrators at state, 
district, and local levels will be implementing program budgeting in 
some fashion for some time to come, because they know neither what 
to do nor how to undo what has already been done with it. More vul- 
nerable than ever to the hard-sales campaign of curriculum peddlers, 
they have made such a fetish of "performance" that children have been 
cast into the role of "performers," to the detriment of other, perhaps 
more important, phases of development. In keeping with this emphasis, 
"behavior modification" has been revived as a legitimate activity;*' 
"chemical straitjackets," in the form of amphetamines, have been used 
to induce docility and conformity in the classroom and thus assure fa- 
vorable "output" for teachers, programs or whatever is being weighed 
in the cost/efTective balance. Skinnerism and other forms of latter-day 
behaviorism are gaining followers in psychology, sociology, and 
education. 

Another direct outcome of the pressure for performance is the 
practice of letting contracts to private companies to conduct specified 
courses in the public schools. In many cases, compensation is supposed 
to be made according to the actual results achieved by the students. 
Funded by Title I of the Elementary and Secondary Education Act of 
1965, contracts had, by the end of 1970, been let by 18 school districts 
in 16 states, as part of the Office of Economic Opportunity program, to 
six companies: Alpha Learning Systems, Learning Foundations, Plan 
Education Centers, Singer Graflex, Westinghouse Learning, and 
Quality Educational Development. "Management support services" 
were supplied to the entire project by Education Turnkey Systems. An 
industry enthusiast, finds the "influx of systems people and companies 
into the staid area of education particularly exciting" and claims that 
the unorthodox methods, such as rewarding children with candy, extra 
free time, or trading stamps, must be good because the National 
Education Association has attacked the concept in Congress, the 
American Federation of Teachers has declared the idea dehumanizing, 



r 



'■Subcommittee of the Committee on Government Operations, House of Representatives, 
Ninety-first Congress, Second Session, "Federal Involvement in the Use of Behavior Modification 
Drugs on Grammar School Children of the Right to Privacy Inquiry," September 29, 1970 (Wash- 
ington, D.C.: U.S. Government Printing Office, 1970. 



157 



JOURNAL OF HIGHER EDUCATION 

and the United Federation of Teachers has sought a court injunction to 
prevent continuation!" 

Evaluation of the OEO experiment, which included some 27,000 
students and cost about $6 million, was, fortunately, not left to inter- 
ested companies, instances of orienting curriculum toward the tests 
and other such abuses having already been revealed. The Comptroller 
General's Report to the Congress provided a noteworthy overview, 
summarized in the following paragraph: 

Was performance contracting more successful than traditional 
classroom instruction in improving the reading and mathematics skills 
of poor children? The answer according to OEO is no! OEO's report re- 
leased in June 1972 stated that "the results of the experiment clearly in- 
dicate that the firms operating under performance contracts did not 
perform significantly better than the more traditional school systems.** 

The imposition upon teachers of performance measures stems from 
the pervasive management-efficiency syndrome and stretches from 
coast to coast. In New York State, a performance-based certification is 
being imposed on teachers; in California, the StuU Act requires that 
teachers be judged on the basis of their pupils' achievement. The New 
York plan has been called an attempt "to evaluate and certify teachers 
on a 'piecework' basis, i.e., how many reading score points were made 
per child."** According to official literature, the Stull Act (Assembly 
Bill 293, July 20, 1971) "provides a unique opportunity for school 
boards and certificated staff members to respond to parent, citizen, and 
legislative demand for educational accountability and to improve 
instructional programs."** 

Especially enlightening is Item C, Criteria for Evaluation: 

Article S.S, Section 13487 of the Stull Act has identified four specific 
steps in certificated personnel evaluation: 

(a) The establishment of standards of expected student progress in each 
area of study and techniques for the assessment of that progress. 

(b) Assessment of certificated personnel competence as it relates to the 
established standards. 



"Thomas DeMarco (Vice Presideiit, Mamiate Systems, Inc., New York), "Software for 
Schools," Modem Data, (December, 1970), p. 46. 

"Comptroller General of the United States, Report to Congress, "Evaluation of Uie Office of 
Economic Opportunity's Performance Contracting Experiment," B-I30SIS, May 8, 1973, pp. 1-2. 

"Sandra Feldman, "Performance-Based Certification: A Teacher Unionist's View," presented 
at AERA, New Orleans, n.d., pp. S-6. 

"California State Department of Education," Certificated Personnel Evaluation in California 
Public Schools. Implementing the Stull Act," Sacramento, California 1973, p. t. 



1S8 



COSTS OF EFFICIENCY 

(c) Assessment of other duties normally required to be performed by 
certificated employees as an adjunct to their regular assignments. 

(d) The establishment of procedures and techniques for ascertaining 
that the certificated employee is maintaining proper control and is 
preserving a suitable environment.** 

Underlying the verbal macram6 of the Act and its attendant docu- 
ments is a shotgun approach to performance. Section (a) in the above 
list of particulars demands that teachers, in order to maintain their 
certification, must guarantee students' progress "in each area of 
study." This being a psychological and pedagogical impossibility, the 
Stull Act makes liars out of teachers or teachers out of the best liars. 
Just as the most egregiously brazen of the performance contractors 
manufactured the most convincing and self-serving "evidence," so will 
those teachers with the fewest scruples survive the trial by pupil 
progress and performance. 



CONCLUSION 



The assumption that education is a system and, therefore, subject to 
the quantified techniques developed for weaponry systems, used in 
space exploration and applied ubiquitously, has brought it to a perilous 
state. Notions of industry-style efficiency have put a premium on 
limited, and not necessarily the most important, aspects of education. 
Where humane and individual approaches are called for, paper-and- 
pencil games ordain mass "solutions." Preoccupation with numbers 
has subverted educational theory and philosophy. Accountability sub- 
stitutes for integrity; the final accounting is a printout that, like an 
infinite hall of mirrors of self-reflection, creates only an endless regress. 
The cause of efficiency may thus be served, but the costs are incal- 
culable and will have to be borne by the whole society, now and in the 
future. 

"Ibid., p. 5. 



159 




foruni 



ji^ '^ fr-i? 



T: 



A continuing fMtur* In which noted individual* in variou* areas ara aelicitad to raport on what i* and thould b« going en 
iff their fields. Response Is welcomed and win appear In the Diicusslen section of future Issues. 



Technology Transfer: Another Opinion 

K. PRESTON WHITE. JR.,> AND DONALD WRIGHT.' In & recent 
Forum [I),* Ida Hoos proposed to argue the case against "Sys- 
tems Analysis as Technology Transfer." The diverse issues 
broached in the Hoos essay are undeniably appropriate subjects 
for serious debate in this Journal. These include the compass of 
the systems approach, the viability of analytic planning, and 
the social responsibilities of the engineering community. The 
Hoos essay, however, is a distressing embarkation on such debate. 

Given a narrow construction, certain elements of the Hoos 
argument are not entirely without merit. Assuredly, some "sys- 
tems analyses" of social problems have failed. And the reason 
for these failures may be traced, in part, to particular analysists' 
lack of imdei-standing of 'the subject they were treating. Indeed, 
quantitative systems analyitis an commonly praetieed in engineer- 
ing and management is not directly applicable to systems which 
are highly complex or varied, or which are incapable of precise 
definition Oi' description, or for which there exist no entirely ac- 
ceptable or optimal solutions. Many of our most pressing social 
problems are rooted in systems which are characterized by all 
of these difticulties. Therefore, the engineering brand of systems 
analysis is not applicable to social systems. Engineers whose 
backgrounds are limited to experiences with engineering" and 
management systems are not competent social planners. 

In all of this, we concur. The engineering community — and 
the public, in general — is well disabused of notions that a tech- 
nology can single-handedly remedy all the ills of our society. In 
fairness, however, much the same must be said for the techniques 
and perspectives of any individual professional community. Our 
major societal problems are neither solely technological, nor 
sociological, nor psychological, nor political, nor economic, nor 
scientific. Our problems are all of these, together, and more. 
It would B<iom that professional communities must work in 
concert if there is to be hope for major societal improvements. 
Perhaps one of the most immedi&te issues confronting the engi- 
neering community is the need for introspection and self- 
criticism, to the end that the community may discern its potential 
contributions to societal improvement and its consequent role 
in interdisciplinary efTorts. 

Our specific contentions with the Hoos essay are twofold. 
First, readers of this Forum unfamiliar with the extent of the 
family of disciplines based upon systems theory arc left with the 
impression that all systems constructs arc useless outside of en- 
gineering applications. Second, readers of this Forum unfamiliar 
with the theses of Thomas Kukn [2] (upon which the Hoos essay 
heavily relies) are left entangled in a web of positive and norma- 
tive assertions regarding the engineering community and the 
"trained incapacity" of engineers to engage in social planning. 



K3rsdtiat« Studant, Department of Meehkniekl Engineerint and Material 
Soieooe, Duke Univenity, Durham, N.C. 

*Auociate Prolemor, Department of Meohanioal l!)ngineering and Ma- 
terial! Science, Duke Univeraity, Durham, N.C. 

'Numbere in bracket* deiignate Refatenoea at end of Forum. 



It b to correct such misimpressions — or at least to present 
another side of a case which legitimately may have more than one 
side— that the present essay is directed. 



Systetns Disciplines 

The gyslemt view is a philosophical perspective which asserts 
universal holism, that is, asserts that every entity in the universe 
is potentially related, to a greater or a lesser degree, to every 
other entity. According to the quality and quantity of these re- 
lationships, entities may be classified together as forming sys- 
tems. In its most general sense, the systems approach is a method 
of inquiry which adopts and utilizes the systems view. 

Systems theory is a science which attempts to formalize, in 
terms of logic and mathematics, the systems view. A com- 
ponent of this formalization distinguishes two basic properties 
of every system: (1) its behavior, the pattern relationships 
between the system and its environment; and (2) its structure, 
"the manner of arrangement (organization) of the mutual 
couplings between the elements of the system [and] the be- 
havior of these elements" (3). Systems theory also distinguishes 
basic types of problems concerning systems, among these: (1) 
systems synthesis, the problem of delimiting a system's structure 
from a known behavior; and (2) systems analysis, the problem 
of determining a system's behavior from a known structure. 

Contrary to the impression fostered by the Hoos' essay, sys- 
tems theory is generally agreed to have originated in biological 
science, not in engineering. The early development of systems 
thought is associated with the biologist Ludwig von Bertan- 
lanify, especially that of General System Theory (4): 

"From the statements we have made, a stupendous perspec- 
tive emerges, a vista towards a hitherto unsuspected unity of the 
conception of the world. Similar general principles have evolved 
everywhere, whether we are dealing with inanimate things, 
organisms, mental or social pressures. What is the origin of these 
correspondences? 

"We answer this question by the claim for a new realm of 
science, which we call General System Theory. It is a logioo- 
mathematical field, the subject matter of which is the formula- 
tion and derivation of those principles which hold for system* in 
general. A 'system' can be defined as a complex of elements 
standing in interaction. There are general principles holding for 
systems, irrespective of the nature of the component elements 
and of the relations or forces between them. From the fact that 
all the fields mentioned are sciences concerned with systems fol- 
lows the structural conformity or 'logical homology' of laws in 
different realms. 

"The principles that hold for systems in general can be de- 
fined in mathematical language. It will be seen then the notions 
such as wholeness and sum, progressive mechanization, cen- 
tralization, leading parts, hierarchical order, individuality, 
finality, equifihality, etc., can be derived from a general defini- 
tion of systems: notions that hitherto have often been conceived 
in a vague, anthromorphic, or metaphysical way, but actually 
are consequences of formal characteristics of systems, or of 
certain system conditions," 



Journal of Dynamic Systems, Measurement, and Control 



MARCH 1975 / 11 



General Systems Theory, then, is vitally concerned with systems 
on the general level at which C. West Churchman defines them 
[5]: "a set of interrelated components working together to ac- 
complish a certain task." A popular (though mathematically 
nonrigorous) application of general systems coneeplioning to 
societal problems is found in R. Buckminster Fuller's Operaling 
ManwU for Spaceship Earth [6], 

The major subdisciplines of systems theory are concerned with 
different realizations of relationships among the elements of gen- 
eral systems. The natural sciences have long studied systems 
from the perspective of mass-energy relationships. A relatively 
new science, Cybernetiet (see, notably, Weiner [7] and Beer [81), 
deals with general systems from the perspectives of organiza- 
tion, communication, and control. Cybernetics is strongly tied 
with a third subdiscipUne, m/ormottpn theory, the science of in- 
formation and communication within systems. Again, these 
disciplines are equipped to deal with systems on a general level. 
As another reader of this Forum has suggested [9], with regard 
to physician W. Ross Ashbey's An IiUrodvction to Cybernetics 
[10], cybernetics also may have a significant practical value in 
ent^neering. The practical value of mass-energy and information 
theories is surely undoubted. 

Other systems disciplines are less general and are biased toward 
consideration of one or another specific class of systems. In en- 
gineering, control theory, informaiion processing systems, and 
communications systems are examples of cybernetic subspecial- 
ties. In urban and regional planning, a discipline increasingly 
called systemic planning is another. The works of Chadwick [4], 
McLoughlin [11], and Catanese and Steiss [12], are notable in 
this context. 

Finally, certain systems disciplines are highly specialized. 
These disciplines employ methods and techniques which are 
predicated upon fundamental (and too often implicit) assump- 
tions regarding the systems question. Among these disciplines 
are, for example, linear control systems, operations research, and 
systems engineering. Systems analysis, the undefined discipline 
to which the Hoos essay is directed, may be thought to com- 
prise both operations research and systems engineering. The 
assumptions, methods, and tools of systems analysis need not 
be catalogued here— it suffices to say they are not always well- 
suited to the consideration of complex social issues. This point 
has been made before and often, most forcefully by Catanese 
and Steiss [U]. The point should be obvious by now. 

Mistaken Impressions 

In attempting to reiterate this simple point, the Hoos essay 
fails to delimit with coherence the problem which it addresses. 
The result of this oversight is the creation of at least two mis- 
taken impressions. First, the essay implies that none of the 
more general systems disciplines are of any potential use in com- 
prehensive planning. The implication is at least debatable and 
we refer the reader to the prcviousiy-cited works on planning for 
a counter-imprcHsion. Second, the essay fosters the impression 
that management science and systems engineering invariably 
fail, even when applied to more narrowly-defined problems in 
societal planning. This implication is not debatable — it is simply 
untrue. 

A lengthy quote from a review of Dr. Hoos' book, Systems 
Analysis in Public Policy (from which the Forum essay un- 
doubtedly is abstracted), is in order. Reviewer Richard de 
Neufville cites many of our own objections [13]: 

"The text itself appears disjointed and fails to build a com- 
pelling argument. The repeated examples of poor analysis, which 
constitute the main part of the book, do not demonstrate whether 
all systems analysis is bad or only part of it is. There is not even 
any indication of whether the examples cited are representative 
of actual applications. As it happens, they frequently are not. 
For example, under the rubric 'the techniques at work in waste 



management,' she describes a single cose. While this one ap> 
plication may be inept, it is quite atypical of how systems 
analysis actually is being vised to expedite garbage collection 
(with some noticeable success, I might add). Similarly, she re- 
peatedly and unjustifiably ascribes parlicitlar statements to the 
whole field. She would, for example, have the reader believe 
that just about all systems analysts were imbued with the idea 
that since we have been able to get man on the moon we can 
solve any problem. Particular anecdotes do not describe a 
problem, and they certainly leave the reader with no guidelines 
for judging the merits of any particular analysis. 

"The presentation is not only weak in concept but also in de- 
tail. It is inaccurate and superficial in form. . . . The author's 
knowledge of systems techniques is, from the context, quite 
weak. Her discussions of areas with which I am particularly 
familiar, social indicators for instance, repeatedly draws in- 
ferences which are not, by any reasonable test that I know of, 
supported by the evidence presented. Furthermore, she is quick 
to impugn motives and to accept slanderous comments un- 
critically. My overall impression is that the text was put to- 
gether carelessly. . . 

"The author has really not given us a reasoned critique, but 
a diatribe. My impression is that she started with the opinion 
that analysis was not only wasteful, but insidious and evil as 
well. It would then seem that she had picked upon systems 
analysis as a particularly vulnerable aspect of analytic planning, 
and launched into an attack without seeing the necessity to 
build a careful case. I suspect that the text should be seen as a 
moralistic statement against the rational model of the planning 
process. As such, it would be part of the growing antitechnology 
movement that is evident in the press and on campuses." 



Semantics and Semantics 

Much of the confusion of. the Hoos essay results from the 
"slippery semantic" issues, about which that essay makes much 
ado. The Hoos essay identifies two "booby traps" which al- 
legedly are responsible for unwarranted attempts to apply sys- 
tems analysis to social systems. The first booby trap is "the 
loose lexicology of the word, system." To prove that the concept 
is vague, the reader is referred to the seventeen definitions pro- 
vided in Webster's dictionary. The reader is assured there are 
more and is treated to the intemperate assertion that, "£very 
writer on the subject seeks to achieve refinement of conceptualiza- 
tion through verbalization, a not uncommon ploy of the written 
word." 

Ploy? We must make the following observations. First, Noah 
Webster is rarely an adequate reference for technical definitions 
(such has been our repeated experience). Second, although the 
technical definitions of "system" are indeed manifold, ranging 
from the verbal to the mathematical, they are each consistent 
with the other (none of the technical definitions to which we 
have been exposed in any way contradict that of Churchman — 
which even the Hoos essay concedes comprises "the generally 
accepted ingredients of a working definition.") Third, if the 
reader requires a rigorous logico-mathematical definition, he ia 
referred to Ellis and Lugwig [14]. Finally, we suggest that this 
definition of system is not vague, i.e., imprecisely defined; 
rather it is general, i.e., of wide applicability. 

The issue of lexicology is not entirely without foundation, 
however. If we concede that scientists — natural, applied, ftnd 
social — can find meaning in the general concept of a system, 
where are the "slippery semantics"? They are, we believe, in 
the definitions of the menage of theory, method, and technique 
abutted with the prefix "systems." "Systems analysis," "sys- 
tems capability," "systems methods," "systems expertise," 
"systems approach," "systems engineering" — all of these are 
used with seeming interchangeability in the Hoos essay. "The 
casual reader, unfamiliar with the family of systems disciplines, 



12 / MARCH 197S 



Transactions of the ASME 



is left with the impression that these and all other systems con- 
structs mean quite the same thing. They do not. 

The second booby trap, is, in Hoos' words, "fallacious analogy, 
for to impute verisimilitude where only superficial similarity 
exists leads to nonsensical conclusions about everything, in- 
cluding skill transfer." This trap is attributed to the "vague- 
ness" — "generality," if you permit — of the word, system. This 
observation is close to the mark, but the problem does not rest 
entirely in the generality of the concept of a system. The burden 
of the problem lies with the concepts of "analogy," "verisimili- 
tude," and "similarity." It is the misunderstanding of thes» 
concepts — concepts which are so much the domain and concern 
of a higher order of "systems expertise" — which in some in- 
stances has led to nonsensical conclusions about skill transfer. 

The Hoos essay is concerned that the readers of this Forum 
have a faulty understanding: of what constitutes "systems 
capability." If this concern is valid, then the essay is remiss in 
simply expounding upon what a systems capability is not. The 
uninformed reader is left with the impression that such capabili- 
ty simply is not. And this is untrue. 

Think of an analogous situation in engineering education. A 
dynamics professor is concerned that his students have a faulty 
understanding of Newton's law. Students have been applying 
/ = ma to problems of variable mass. As a consequence, they 
have been wasting their time, burning up valuable resources in 
graphite and theme paper, and the problems are still unsolved. 
To correct this "amorphous state of conceptuaUzation," the 
professor lectures that it has been repeatedly demonstrated that 
f = ma does not apply to rocket problems, because the mass of 
the rocket varies. What has this lesson taught? Hopefully, it 
has taught that/ => 7na does not apply to variable-mats problems. 
For students that know Newton's law only as/ •> ma, the lesson 
also has taught that Newton'i law does not apply to rocket prob- 
lems, which clearly is untrue and is not what the professor in- 
tended. Has the students' conceptualization if rocket problems 
or Newton's law been improved? Yes and no. What the Hoos 
essay teaches is that systems analysis does not apply to social 
problems. To the reader who knows the field of "systems" 
only aa systems analysis, the lesson has also taught that a "sys- 
tems approach" does not apply to social problems. The worth of 
this lesson we leave to the reader's judgment. 

Paradigms 

Our second contention with the Hoos essay regards its charac- 
terization of the engineering community. This characterization 
leads to suggestions as to the appropriate means by which in- 
dividual engineers and the engineering community at large 
must seek social relevance. To appreciate fully what the Hoos 
essay attempts to do, one must be familar with the theses 
Thomas Kuhn advances in bis exceptional essay, The Structure 
of Scientific RevoliUions [2). To do justice to Kuhn's essay in 
this limited space, of course, is impossible. Therefore we shall 
attempt to summarize only two theses which arc particularly 
germane to the present discussion. 

Kuhn invokes two related concepts, both of which are meant 
by the word paradigm. The f.rst and general meaning of para- 
digm is, in Kuhn's words, "disciplinary matrix": examples, 
beliefs, models, values, generalities, and so on, shared without 
dissent by members of a professional community. It is this 
sense of the word which the IIoos essay intends in iU definition 
of paradigm "as a fundamental way of perceiving, thinking, and 
doing, consistent with a particular vision of reality." . 

The second, more specific, and more original meaning of para- 
digm is, again in Kuhn's word.s, "exemplars" : shared examples 
which the student experiences as an essential part of his initia- 
tion into the particular vision of reality held by the professional 
community. Kuhn's thesis is that the science student assimilates 
"a time-t«.stcd and group-licensed way of seeing" by "doing 



science rather than by acquiring rules of doing it." Solving 
problems — both textbook and laboratory problems — does not 
merely or even primarily serve as a medium for gaining facility 
in applying the theory and rules of science, rather "doing prob- 
lems is learning consequential things about reality" [2]: 

"The student discovers, with or without the assistance of his 
instructor, a way to see his problem as like a problem he has 
already encountered. Having seen the resemblance, grasped the 
analogy between two or more distinct problems, he can inter- 
relate symbols and attach them to nature in the ways that have 
proved effective before. The law-sketch, say / •" ma, has func- 
tioned as a tool, informing the student what similarities to look 
for, signaling the gcstalt in which the situation is to be seen. 
The resultant ability to see a variety of situations as like each 
other, as subjects for/ = ma, or some other symbolic generaliza- 
tion, is, I think, the main thing a student acquires by doing ex- 
emplary problems, whether with a pencil and paper or in a 
well-designed laboratory. After he has completed a certain 
number, which may vary widely from one individual to the next, 
he views the situations that confront him as a scientist in the 
same gestalt as other members of his specialists' group. For him 
they are no longer the same situations he has encountered when 
his training began." 

Engineering educators, no doubt, already are convinced of this 
thesis. 

Perhaps Hoos' strongest argument opposing engineers' en- 
deavors in social planning is founded upon these concepts of 
paradigms. The exemplars which the engineering student learns 
are not always consonant with exemplars relevant to sodal 
systems. The vision of reality the engineering student acquires 
through the assimilation of these exemplars — the vision of 
reality of the engineering community — is not always a vision 
appropriate to social planning. The engineer "sees" systems as 
"things;" social systems are "ideas." The engineer tackles ft 
problem as though it had a single, objective "solution;" social 
problems have no consensus "solutions," per se. En^neering 
problems are "value-free;" social problems are "value-laden." 

As a general assessment of the majority engineering com- 
munity, this recognition is compelling. However, it is no more 
than a generality. The engineering community is not so mono- 
lithic as the Hoos essay would have us believe it is, or should be, 
or must be. There are substantial numbers of engineers whose 
vision of reality t« consonant with the reaUty of social systems. 
This vision has been conditioned not only upon "traditional" 
engineering exemplars, but also upon exemplars of the social 
sciences and of general systems theory. This "different vision" 
has not precluded their competence as practicing engineers. It 
has allowed them competence in planning. 

There is, in our opinion, a particular aspect of the engineer- 
ing general paradigm which, when coupled with the appropriate 
exemplars, allows engineers to be particularly good planners. 
This is, for want of a better phrase, "purposeful, explicit assump- 
tion-making." The engineer is willing to make assumptions about 
reality, not because he believes that his assumptions are true 
(in some objective sense), but because they "work." "What 
works," in turn, only has meaning in terms of one's goals and 
objectives. A digression upon pragmatic philosophy, linguists, or 
gestalt psychology is beyond our competence (our rather limited 
introduction to these subjects includes Dewey [15], Russel (16), 
Polanyi [17], and Postman and Wcingartner (18)), but we suggest 
that the engineering approach creates a "focal awareness" (to 
borrow Polanyi's term) of the process of assumption-making. 
In engineering, this awareness bounds the process of finding 
solutions. Coupled with the appropriate exemplars and a cautious 
redefinition of "what works," this awareness can be the driving 
force behind a planning process which seeks not "social solutions," 
but "social improvement." Certainly improvement may be pos- 
sible. 



Journal of Dynamic Systems, Measurement, and Control 



MARCH 1975/ 13 



The Engineering Community— Positive Assertions 

A second of Kuhn's theses is that, to understand science, it 
is necessary to study the structure of the scientific community. 
Although Kuhn refers expressly to science, not technology, the 
thesis extends to include other disciplines as well. - 

"I shall dose by underscoring the need for similar and, above 
all, for comparative study of the corresponding communities in 
other fields." 

Kuhn proposes a number of questions appropriate to this study. 

"How does one elect and how is one elected to membership in a 
particular community, scientific or not? What is the process and 
what are the stages of socialization to the group? What does the 
group collectively see as its goals; what deviations, individual or 
collective, will it tolerate; and hew docs it control impermissible 
abberation?" 

These are precisely the questions which, for the engineering 
community; the Hoos essay poses answers. These answers are 
somewhat confused between the positive and normative modes — 
between the "is" and the "ought" — but they are worthy of un- 
ravelling. 

In the positive mode, the Hoos essay asserts that engineers 
elect to membership because they have "a basic lack of sociabili- 
ty" and "low people-orientation." The socialization process be- 
gins with exemplars that are "thing-" and not "people-" or 
"idea-oriented." The engineer is isolated physically and ethically 
from the society at large. The resulting ethical myopia is rein- 
forced by his station as an employee of industry or the military: 
he has little control over the technological change he helps to 
create and consequently refuses to accept responsibility for that 
change. He learns to do what he is told. He seeks solice in "doing 
his thing well," the principal value of the group. The community 
also values ethical conduct between engineer and colleague and 
between engineer and employer, but not between engineer and 
society at large. The values of the group are enforced, pre- 
sumably, by the marketplace. 

The Hoos essay also recognizes a new and dissonant clement in 
the socialization process. At some time in the process of being 
or becoming an engineer, one is afflicted with "what the psychia- 
trists call a 'collective unconscious guilt'." This guilt is a product 
of the engineering community's "heritage couched in the mili- 
tary." It is to assuage this guilt that the engineer seeks "rele- 
vance." The engineering community has come not only to con- 
done relevance-seeking as appropriate activity for engineers, but 
has come to adopt relevance itself as a group value. "Engineers 
en nuuae are exhorted by deans of their colleges to turn their 
talents to solving the amorphous mess known as social prob- 
lems..." 

Following Kuhn's work, this dissonance is the beginning of a 
guilt-induced "paradigm-shift." The engineering community is 
redefining its values, changing its self-image and the image of 
what engineering is about. Hoos desires to forstall such a shift. 
The problem, as Hoos sees it, is that the tools and exemplars of 
the community are not changing accordingly. Relevance is being 
sought in the wrong place — social planning — where engineers 
have no competence. 

Before considering the normative assertions of the Hoos 
essay, it is appropriate that we look at this posivive characteriza- 
tion more closely. As a caricature, this description of the com- 
munity may not be far from fact. Unpleasant, but with elements 
of truth. It is, of course, no more than a caricature — a generality 
with salient features exaggerated. 

What we (iiul (lillicult to aocopt is the notion of "colleotive 
unconscious guilt" as the motivating force behind rolflvtiiice- 
secking. We enrnmtly wish to question Hoos' sourcos to this 
point, but she cites none (which, in light of her scrupulous 

14 / MARCH 1975 



documentation of Shakaspeare, is particularly odd). "With no 
pejorative intent," we suspicion that Dr. Hoos' knowledge of 
psychiatric science is on a par with her understanding of systems 
science. At any rate, there seems an equally plausable explana- 
tion. This is the very conscious recognition that, here and now, 
the engineering community is participating in activities which are, 
to some, morally repugnant. Seeking relevance is seeking alter- 
natives to participation in those activities, in real time. 

We have steadfastly endeavored to refrain from the emotional- 
ism which characterizes the Hoos essay, but there is one image 
which we can not seem to shake. If the reader will please forbear, 
we are reminded of Arlo Guthrie's reaction, in Alice's Restaw 
rant [16], when he finds he has been withdrawn from the selec- 
tive service pool, because he was once convicted of littering in 
Stockbridge: 

"I mean. . .I'm sittin' here on the Group-W bench, because you 
want to know if I'm moral enough to join the Army, bum 
women, kids, houses and villages, after being a litterbug?" 

We have often felt thai way about engineering. 

The Engineering Community— Normative Assertions 

The only consistent, normative motif of the Hoos essay, re- 
garding what the engineering community should do, appears to 
be the prejudice that engineers should avoid social planning, 
because they are and always will be inept at it. Refusing to 
admit any present competence, or any possibility of future 
competence, the Hoos essay advises that the conununity dis- 
courage "crossover" or "passing," not only among engineering 
disciplines, but between engineering and the social sciences. It 
is suggested that such discouragement can be affected by de- 
manding specialization: a long history of specialization has made 
engineering great and justifies a return to the original paradigm. 

Specialization, of course, will keep engineers out of the social 
arena. But the problem of "guilt" (or current irrelevance' of the 
old paradigm) is not solved. The dissonance giving rise to the 
new paradigm cannot be wished away so easily. History pro- 
vides no justification, in i.tself, for we are told (in almost the 
next breath) that it is this same history which causes the "guilt." 

If he (or she), must purge himself of thb guilt, the engineer 
is advised that there are many relevant activities which he 
should pursue within his specialty. An admirable list is offered. 
But if we are operating under the old paradigm of engineer-as- 
employee, doing well only that which he is told to do, from where 
docs the power emanate by which the engineer demands the 
opportunity to pursue these relevant activities? Employers, 
including the manufacturers of medical equipment, construc- 
tion companies, and Detroit, are not necessarily motivated by 
an altruistic concern for safer products. Profit is often an over- 
riding concern. Either relevant projects appear without the in- 
tervention of the engineering community (industry changes its 
paradigm), or the engineering community must learn to demand 
their undertakings. Specialization is not the key to that kind 
of learning. 

The second, guilt-relieving suggestion offered by the Hoos 
essay is denegation. 

"Perhaps it is not the engineers who should be bleoned for be- 
having true to form, in only doing what is asked of them... 
Perhaps we should look farther and direct our criticism to govern- 
ment agencies who should know better." 

Two questioils surface in this regard. First, can this strategy be 
successful within the old paradigm? Second, if it can, should 
the community adopt this strategy? To the first and positive 
question, wo submit that simple denial is precisely the strategy 
whi(Ji historically has M to guilt. Denial, coupled with rational 
analysis, however, might work. The level of consciousness of the 
group could be raised and consciousness of the previously ua- 

Transactions of the ASME 



conscious guilt would allow its treatment. The community could 
then accept its employee utatus and no longer feel guilt in regard 
to that over which it has no control. But this new consciousness 
is of the new paradigm, not the old. And it permits a positive 
rephrasing of the second and normative question. Would such 
an enlightened community actually have no control over the 
results of technology? 

We think that it would. The traditional "cop-out" of the 
engineer has been, "if I didn't do it, someone else would." This 
rationalization would no longer avail in an enlightened com- 
munity. That "someone else" is invariably an engineer. The 
enlightened engineering community would militate against the 
"someone elses" among its fold. 

Regardless of the viability of Hoos' prejudice, the old para- 
digm is no longer viable once the engineering community ac- 
knowledges that it has made and is making ethical mistakes with 
regard to society at large. The paradigm has changed and there 
is no returning. Specialization can not force such a return. The 
options open to the community are either to do something as- 
sertive to gain relevance, or learn to live with irrelevance. The 
latter course, we feel, is highly undesirable. 



Conclusions 

In the first part of this essay, we have attempted to forestall 
the equating of "systems analysis" with the entire field of sys- 
tems disciplines. With this erroneous equation goes the notion 
that a systems approach is valueless outside of engineering. We 
have suggested, in fact, that the more general sy.stems disciplines 
can and have had some success in social planning, albeit at a 
strategic level. We have offered the opinion that an expertise 
in these general constructs, coupled with an understanding of 
social phenomena, eventually may lead to the development of 
specific tools for social systems analysis. 

In the second part of this essay, we have attempted to show 
that specialization is not a curative for the engineering com- 
munity's dilemma of social responsibility. The mode of "doing 
well what one is told to do" will be dissonant with the value of 
"achieving something relevant" as long as the engineering com- 
munity remains the irresponsible servant of other social com- 
munities. Specialization can help the engineering community 
to do what it does well, but can not insure the relevance of that 
activity. It is cncumbant upon the engineering community to 
ask the question, "What is worth doing?" It is encumbant upon 
the engineering community to seek the means by which they 
may act upon the answers to this question. 

The present trend in engineering education is of the new 
paradigm of awareness and social responsibility. This paradigm 
may provide a resolution to the conrununity's dilemma: a 
socialization process which stresses the community's ethical and 
moral responsibilities to society at large. If the trend persists, 
the engineer eventually may be able to say, "If I don't, nobody 
else will." 

Aspects of the problem identified in the Hoos essay are valid, 
but the solution is not simply to retreat into specialization. The 
engineer wishing a specialty should have one. The community 
should guarantee that the activities of that specialty are relevant. 
But the engineer wishing to tackle problems of generality should 
not be dissuaded. The community should encourage him and 
provide him with the appropriate theory and exemplars. It is 
our opinion that the theory of general systems and the combined 
exemplars of engineering and social science are appropriate to 
that task. It is the engineeriFig generalist who will create a role 
for himself in much needed interdisciplinary cfTort.s. 

The major problems of our society may have no immediate or 
enduring solutions. If such solutions do exist, they will never 
be found through the techniques of any particular discipline, or 
any combination of such techniques. The tools appropriate to 
that quest arc trust, generosity, and human uiulcrstanding. But 



the lack of solutions should not end the search for improve- 
ment. No doubt, there is much that can be improved. 



Acknowledgments 

The authors greatly appreciate the thoughtful criticisms and 
suggestions made by our graduate student colleagues and 
especially by Dr. N. B. Ratliff, Jr. The responsibility for the 
opinions expressed in this essay, of course, remains our own. 



References 

1 Hoos, I. R., "Systems Analysis as Technology Transfer," 
Journal of Dynamic Systems, Measurement, and Control, 
Trans. ASME, Vol. 96, No. 1, Mar. 1974, pp. 1-5. 

2 Kuhn, T. S., The Stniclure of Scientific Revolutions, Univer- 
sity of Chicago Press, Second Edition, Fourth Impression, 1973. 

3 Klir, Jiri, and Valach, Miroslav, Cybernetic Modelling, D. 
Van Nostrand Co., Inc., 1966. 

4 Chadwick, George, A Systems View of Planning, Pergamoa 
Press, 1970. 

5 Churchman, C. W., quoted in Hoos, op. cti., p. 1. 

6 Fuller, R. B., Operating Manual for Spaceship Earth, 
Pocket Book Edition, Fourth Printing, 1972. 

7 Weiner, Norbert, Cybernetics, Wiley, 1948. 

8 Beer, Stafford, Cybernetics and Management, Wiley, 1952. 

9 Porter, B., "Cybernetics and Control Engineering," 
Journal op Dynamic Systems, Measurement, and Control, 
Trans. ASME, Vol. 95, No. 4, Dec. 1973, p. 349. 

10 Ashbey, R. W., An Introduction to Cybernetics, Wiley, 
Third Impression, 1958. 

11 McLoughlin, J. B., Urban and Regional Planning: A 
Systems Approach, Praeger Publishers, 1969. 

12 Catanese, A. J., and Steiss, A. W., Systemic Planning: 
Theory and Application, Lexington Books, Second Printing, 1972. 

13 de Neufville, Richard, "Book Reviews: Systems Analysis 
in Public Policy. A Critique— Ida. R. Hoos," Transactions on 
Systems, Man and Cybernetics, IEEE. Sept. 1973, pp. 532-633. 

14 Ellis, D. 0., and Ludwig, F. J., Systems Philosophy, 
Prentice-Hall, Inc. 1962. 

15 Dewey, John, The Quest for Certainty, Capricorn Books 
Edition, Tenth Impression, 1960. 

16 Russel, Bertrand, The Impact of Science on Society, Simon 
and Schuster, 1953. 

17 Polanyi, Michael, Personal Knowledge, Harper Torchbook 
Edition, 1964. 

18 Postman, Neil, and Weingartner, Charles, Teaching as a 
Subversive Activity, Delacorte Press, Third Printing, 1969. 

19 Guthrie, Ario, Alice's Restaurant, Reprise Records. 



Author's Reply to Technology Transfer: Another 
Opinion' 

White and Wright's "other opinion" is to be commended, 
especially for reinforcing, sometimes positively, more often 
negatively, many of the salient points made in my Forum 
article (March, 1974). One might have wished, however, that 
they had not fallen into several of the booby traps I warned 
against. Their main concerns are that the reader was left (a) 
"with the impression that all systems constructs arc usetess 
outside of engineering applications," and (b) "entangled in a 
web of positive and normative assertions regarding the engi- 
neering community." 

The first item illustrates tellingly the very semantic slippage 
which I described and which they criticize me for emphasizing. 
Their scholarly di.ssertation on lexicology sheds scant elucida- 
tion. In it, they make the usual appeal for faith in the meaning 
implicit in "the general concept of a .system" but fail to articulate 
what this meaning is. Then, they perform a delicate pas de deux 



•By K. Freaton White aud Donald Wright. 



Journal of Dynamic Systems, Measurement, and Control 



MARCH 1 9 7 5 / 15 



about the perceptions of the dbccrnitig, as opposed to those of 
the casual, render. With the claim that I misled the hitter into 
thinking that all sorta of systems constructs mean the same thing, 
they state authoritatively and without definition, "They do 
not." This kind of disputation is straight out of Alice in IVonder- 
land, her famous dialogue with H-jmpty Dumpty-going as fol- 
lows: 

"When I use a word," Humpty Dumpty sMd in a rather 
scornful tone, "it means just what I choose it to mean — 
neither more nor less." 

"The question is," said Alice, "whether you can make words 
mean so many different things." 

"The question is," said Humpty Dumpty, "which is to be 
master— that's all."' 

Humpty Dumpty makes an important point; the Wellan- 
tehauung (world view) of the analyst, his perception of the sys- 
tem, his selection of variables as to relevance aud pertinence, 
his assignment of priorities, his value system — all of these are 
crucial in dealing with the spectrum of constructs we have 
crudely labelled syglemt, and tha more so when dealing with the 
amorphous construct, social systems. In short, the vital factor is 
who it master, that's all. 

Humpty Dumpty thus brings us to White and Wright's second 
bone of contention, namely, the engineer as system designer, 
architect, or analyzer. In choosing to focus on my discussion of 
the trained incapacity of engineers, they inadvertently substan- 
tiate rather than refute my position. They could have argued 
that trained incapacity, even though originally attributed by 
Veblen to engineers, is neither limited to nor exclusive with that 
profession. They did, rightfully, insist that the notion of systems 
theory is not the private preserve of engineering, and they cite 
Bertanalffy in biology. Churchman in operations research, and 
R. Buckminster Fuller, wherever he may be. They could have 
delved into many more streams of intellectual history, as I 
already have done.* They could even have carried their argu- 
ment a step further and maintained that not only in its origins 
but in its current applications the usage of the systems approach 
is not the bailiwick of engineers alone. It has, as I have pointed 
out elsewhere, become the stock-in-trade of the "brains-for- 
hire," which often consist of pick-v,p crews from a motley of 
professions, not excluding sociologists! If they had made this 
point, I would have been forced to consider more seriously the 
phenomenon, "everybody's doing it," which I tried to explain 
briefly by evoking (and not, as they imply, leaning heavily on) 
Kuhn's notion of the "dominant paradigm."* 

Had the authors pursued this course, I might have had to 
concentrate on what I consider the more basic issues, which do 
not concern who is doing it, nor even why they are doing it,* so 
much as what it is they are doing, whether it is appropriate, and 
what are its present and likely effects on planning policy and 
practices. What they are doing cannot be divorced from engi- 



>Lewu Curoll, Through tht Looking OUu; Grouet A DunUp, New York' 
1940, pp. 280-31. 

*For more compreheiuive treatment of thia and other aspects of subject, see 
Ida R. Hooe, Syatemt Analytit in i'uili'e Policv: A Critiqut, University of 
California Press, 1073. 

'I could have stated this another way and cited the prevailing mytliology 
of metho<lology, persuasive wherein is the message conveyed in the story of 
the emperor's new clothes. 

*I was being charitable when I attributed the engineers' quest for social 
relevance to a possible guilt complex. Despite current trends in government 
and foundation grantsmanship, I was reluctant to impute tliis urge to "do the 
society good" to motives less noble and altruistic, such, perhaps, as oppor- 
tunism. 



nccring, for even though the systems approach may have origins 
OS dtfFuae ns its definitions, its technical trappings and its iiuicro- 
niachismfi stem directly from its iutimntc association, inside or 
outside of wedlock, with engineering. Appeals to the large 
wholeness of social phenomena (and hence the need for "sys- 
tems" thinking) and facile elisions from "systems thinking" to 
"thinking systematically" notwithstanding, the systems approach 
in practice is a particular, identifiable method, which, I main- 
tain, is neither appropriate nor adequate in the sphere of human 
and social "systems" understanding, let alone design and man- 
agement. Rather than provide any more horrible examples, and 
so ns not to leave even the casual reader with any doubts on this 
matter, I would refer him to Georgescu-Roegen's' scholarly refu- 
tation of the mechanical analogue in economic process, equally 
devastating when directed to all social process. After showing 
that logic and rationality, the main articles of faith in the engi- 
neers's credo, can handle only a very restricted class of concepts, 
George.scu-Roegen asserts that (1) wholesale arithmetization (I 
prefer the term quantification) is impossible; (2) there is valid 
knowledge even without arithmetization; and (3) mock arith- 
metization is dangerous if peddled as genuijie (my underlining).* 
He then introduces and develops the concept of erdropic indeter- 
miiuUeness, which is based on thermodynamic principles and 
which, when applied to systems of economics (and other social 
activities), throws into sharp perspective the fundamental de-. 
ficiency inherent in the systems approach as now applied as a 
nostrum for society's ailments. 

It is unfortunate that the authors chose to debase what could 
have been scholarly discourse by resorting to the vade mecum 
tactic of reinforcing their position by incestuous validation from 
within the trade, as seen in the quotations from the lEE review 
of my book, Systems Analysis in Public Policy* They could, . 
as a matter of fact, have drawn on a more distinguished journal, 
/Science,'* which devoted two pages to a similarly intemperate 
attack by an engineer connected with "a Program in Engineering 
for Public Systems." He, in turn, had invoked as validation for 
his position an angry letter to the editor of Management Seienee^^ 
by another engineer , protesting my views on management in- 
formation systems, which,, incidentally, his areospace company 
employer peddles at a great rate! But this type of exercise can 
impress only the unenlightened. Such instances serve more to 
strengthen my contention about the engineers' generally limited 
world view than to enhance the cause of intellectual advance- 
ment. That the book and my widely published writings have 
received commendation from authorities representing a broad 
spectrum of disciplines, not excluding engineering, conveys a 
message more significant than the outraged cries of the wounded 
species. 



•l«at I be accused of hyperbole, the following are excerpts from a letter from 
the Univeraity of Illinois Press (October 34, 1973): 
Dear Reader: 

"Mow can scientific methods be applied to solv ing urban problemsT 
Are problems of trafnc congestion, accidents, noise and nuisanoe sotvabiaT 

Should restrictions be placvd on privately owned automobiles? 
Can close coordination between travel and land use planning be achieved? 

Does politics play too great a role in urban planning? Is urban planning 
really encouraged and sustained for sociological betterment?" 

The sales pitch is then made that a "scientific approach to urban aoalyai*." 
which brings together "scientific techniques from mathematics, operation! 
research, systems analysis, information science, and planning," exists (and ia 
particularly useful form in the books being proipoted)! 

'Nicholas Qeorgescu-Roegen, Tht Entropy Laa and tht Beonomic Proout, 
Ilsrvaid University Press, 1971. 

*Ibid., p. 16. 

•cp. ei't. 

«Seitnu. Vol. 17, November, 1973, pp. 739-40. 

^UanoQtmont Seitneo, February, 1072. 



16 /march 1975 



Transactions of the ASME 



Appeals to the claque notwithstanding, the compelling ques- 
tion still remains as to the appropriateness of the tools and tech- 
niquas being transferred. As I pointed out earlier, Georgescu- 
Rocgcn's methodologically reiined analysis of the shortcomings 
and dangers should be understandable in his own terms to the 
engineer. Moreover, if as the authors seem to imply, there is 
validity to the argumerUum ad nominem, one might suggest 
that they draw on the wisdom of the more talented among their 
numbers, — none other than Norbert Weiner, who cautioned 
precisely against this kind of inappropriate transfer, questioned 
whether it was useful or honest, and even suggested that it was 
a sham and a waste of time.'' 

Ida R. Hoos 

Space Sciancas Laboratory 
Univarslty of California 
Barkalay, California 
Novambor 1S74 



Dynamic Systems Analysis 
in Interdisciplinary Research 

ROBERT C. SPEAR.i At the 1974 Joint Automatic Control 
Ck>nference, 39 of the 86 papers presented dealt with topics out- 
side the traditional subject areas of control engineering and 
dynamic systems theory. lu particular, six papers concerned 
dynamic aspects of biosystems and 28 addressed ecological and 
environmental subjects. To one who left control engineering to 
work in the environmental sciences some years ago, the de- 
velopments signaled by the subject distribution of the JACC 
papers are of great interest. It would appear that the vigorous 
development of dynamic systems methodology by engineers and 
applied mathematicians in the last several decades has now 
culminated in a widespread recognition of the relevance of the 
theory to various other disciplines based in the natural sciences. 
The relevance of dynamic system theory to biology, for example, 
was historically demonstrated by pioneers like Lotka [!]> but 
its broad application and inclusion in teaching programs is a 
recent phenomenon. 

Most of the productive applications of dynamic system 
methodology can be classified as either scientific or technological 
in nature. The scientific applications are typified by the writings 
of Rosen [2) and May 13) which are essentially aimed at the 
elucidation of the dynamic aspects of scientific problems in 
biology. The technological or engineering type applications are 
exemplified in the environmental sciences by the work df Young 
and Beck [4] in their study of the temporal variations and con- 
trol of water quality parameters in an English river. A common 
feature of many of these technological applications of dynamic 
system theory is that the problem requires the input of various 
disciplines for its solution. It is often the integrative nature of 
systems methods that is particularly valuable. However, few 
problems outside engineering can support an individual who 
serves only as a dynamic systems analyst. Therefore, to maxi- 
mize the benefit to be gaineci from the dynamic systems point of 
■view in interdisciplinary work, it can be argued that we must 
despocializc and refocus our attention on the problem rather 
than the methodology used to solve it. There is no doubt that 
there is increasing scope for dynamic systems analysts in gen- 



»Narbert Wiener, Qod A (M<m, Inc., 1964, pp. 87-92. 

■Department of Uiomedical and Environmental Health Sciences, Univenity 
of California, Uerkeley, Calif. 

'Numbers in braeketa deaignate References at end of Forum. 



eral and control engineers in particular to work in the environ- 
mental sciences, the health sciences and in a variety of other 
interdisciplinary areas. However, for those who choose to pursue 
this course, new subject matter will have to be learned and the 
security of a clear technical identity may have to be abandoned. 
The reward of such a transition is potentially to contribute new 
insights, different technical viewpoints, and new approaches to 
interdisciplinary problems. 

Underlying this view of the potential role of dynamic systems 
theory in interdisciplinary work is this writer's experience that 
its major contribution is strategic rather than tactical. That is, 
it is the basic perception of the temporal nature of many problems 
and the ability to conceptualize the processes basic to their 
understanding in terms of system state, for example, that appear 
to be the potentially important contributions. One seldom en- 
counters a problem, although they must exist, where knowledge 
of the best estimation algorithm or a particular theorem from 
optimization theory is the crucial factor. On the other hand, 
it is often useful to have at hand some generally useful computer 
codes for estimation or simulation work. 

By way of a concrete example, our group is engaged in a re- 
search project aimed at determining the mechanisms by which 
agricultural field workers can become ill from exposure to foliar 
residues of certain pesticides while harvesting the crop. Ulti- 
mately, such research will provide the basis for the establish- 
ment of sound protective strategies. The array of spedalized 
knowledge relevant to the solution of this problem ranges from 
agricultural chemistry to toxicology with elements of the fields 
of industrial hygiene, clinical medicine and soil science being of 
equal importance, to name but a few. However, the key to the 
problem does not appear to lie in any single specialist's domain. 
As with many problems in environmental toxicology, it is the 
integration of the contributions from each discipline into a 
scheme which displays the interrelationships between variables 
as well as the dynamics of the system which appear to hold the 
greatest promise for elucidating the factors important to an 
understanding of the problem (5). For example, a determination 
of the rates at which the pesticide decays and metabolites of 
toxicological significance are produced on the foliage is of im- 
portance as are the effects of environmental variables on these 
processes. This aspect of the problem lends itself to straight- 
forward differential equation modeling of the form k(0 — I(k(0 
?(0i 0. where x(0 is the vector of chemical species of toxicological 
interest in the foliar residue and ?(f) is a set of parameters as- 
sociated with environmental variables. The functions f tend to 
be poorly defined but in specific cases studied to date the ap- 
proximations and assumptions usual in engineering practice 
have been useful. For some of the more important pesticides, 
it appears that the hazard to workers is a function of the scalar 
y = e''x, where c is related to the relative toxicity of the chemical 
species. 

Intermediate between these chemical processes and the toxi- 
cological processes are a host of variables associated with the 
exposure, mechanism. These variables concern work practices, 
work rate and other factors similarly difficult to quantify but 
all of which mediate between the environment and the dose ab- 
sorbed by the worker. The conceptual or symbolic modeling of 
these less well-defined processes has been a useful means of in- 
tegrating the diverse data and, in particular, of delineating the 
causal relationships between variables. 

In common with the environmental phenomena, the absorp- 
tion of the pesticide through the dermal and respiratory bar- 
riers, the kinetics of its binding with the target enzyme system 
and its eventual excretion from the body arc all phenomena for 
which a temporal interpretation is demanded. However, our 
inability to quantify the exposure mechanism places an upper 
bound on the modeling effort that can be justified on the environ- 
mental or toxicological components of the problem. There is 
a natural tendency, nevertheless, to focus on those processes 



Journal of Dynamic Systems, Measurement, and Control 



MARCH 1 9 7 S / 17 






Journal of Atmospheric and Terrestrial Physics, 1975, Vol. 37, pp. 119-129. Pergamon Press. Printed In Northern Ireland 






Propeities of the wake o£ small Langmuir probes 
on sounding rockets 

E. A. Bering 

Physics Department, Space Sciences Laboratory, University of California,* 
Berkeley, California 94720, U.S.A. 

{Eeceived 20 November 1973; in revised form 27 February 1974) 

Abstract — Split Langmuir probes have been used to study the near wake of small Langmuir 
probes on sounding rockets. The split Langmuir probe is a device which performs the usual 
measurement of current versus voltage for the two halves of a probe and, in addition, measures 
the difference current between the two halves to accuracies the order of 10~* times the single 
half plate current. Thus it is an ideal instrument for studying the near wake of a small probe. 
Experiments have been performed on two rocket flights using planar disk and cylindrical 
geometries and the results presented in this paper. Significant wake perturbations in plasma 
density and temperature were found due to the probe body itself, even though the probes 
were the order of or smaller than the Debye length. The largest effects of the wake are seen 
in the electron collection characteristics of the probe. The wake of small probes show apparent 
magnetic field aligned structure, even though the probes were much smaller than the ion 
gyroradius. On one flight, a space charge potential large enough to substantially alter photo- 
emission, — 3-5 volts, was observed. 

1. Inteoduction 

One of the oldest and most fundamental technical problems confronting the 
experimental space physicist is the interaction of the rapidly moving vehicle and 
instruments with the ambient medium. Low altitude spacecraft and ionospheric 
sounding rockets usually have velocities relative to the ambient medium greater 
than or comparable to the ion thermal velocity. It can be expected that such a 
spacecraft would have a substantial wake. Numerous experimental results have 
supported this hypothesis (Boedeatt and Donley, 1965; Samir and Willmoee, 
1965; Hendeeson and Samie, 1967; Samie and Weenn, 1969, 1972; Weenn, 
1969; Samie, 1970; Oya, 1970; Millee, 1972; Samib et al, 1973). A review of the 
problem was given by Liu (1969). 

Several approximate theoretical models have been made of the problem, but a 
quantitatively adequate general solution has not yet been attempted due to the 
difficulty of the problem (Gueevich et al, 1969; Samie and Weenn, 1969; 
BoGASHCHENKO et al., 1971; Samie and Jew, 1972). Experimenters attempting 
to make probe measurements of ionospheric plasma parameters have had to use 
extreme care in treating the wake problem when interpreting and analyzing their 
data. One approach is to assume that a boom mounted probe, comparable to or 
smaller than the Debye length in at least one dimension, many Debye lengths 
from the spacecraft, and oriented at right angles to the direction of travel, is not 
affected by wake problems (Samie and Willmoee, 1965; Findlay and Brace, 
1969; Beacb et al., 1971). The wake of the probe is typically ignored. The purpose 
of this paper is to present data on the structure of the wake of probes with dimensions 
on the order of the Debye length flown on two sounding rockets. 



Now at: Department of Physics, University of Houston, Houston, Texas, 77004, U.S.A. 

119 



120 E. A. Bering 

The Instbtjment 

The instrument used for this study was a split Langmuir probe (Bering et al., 
1973a,b), which consists of two parallel conducting plates or two opposite conducting 
hemicylinders, separated by an insulator. The plates are maintained at the same 
potential, which is periodically swept. The current to one plate, /j, and the difference 
current between the plates, I^ — I^, are measured as functions of the plate voltage. 
Two such probes were flown on each rocket, one mounted with the normal to the 
probe surface perpendicular to the spin axis, and the other, mounted with its 
normal parallel to the spin axis. The probes were deployed on | meter booms 
mounted at the forward end of the rocket payload. The results from the first 
of the two flights discussed here and the details of how the instrument works have 
been discussed in two previous papers (Bbeing et al., 1973a,b) called papers I and 
II respectively. 

On the two flights discussed in this paper, the voltage sweep rate of the perpen- 
dicular probe was fast compared to the spin rate. Thus, the plasma density and 
temperature deduced from the current characteristic of one plate can be analyzed 
as a function of spin phase. The directional nature of the single plate of the split 
probe gives the instrument the capability of detecting its own wake as the rocket 
spins. It is assumed that forward mounted, boom deployed probes are not affected 
by the vehicle wake, at least on the upleg. Therefore, any wake phenomena 
detected can be attributed to the probe itself. 

Analysis of the difference current as a function of potential and spin phase 
can yield further information about wake structure. As shown in paper II, the 
difference current at positive or negative potentials is given by 

AJ = neAd . t;^ for F < (1) 

M = neAd . v, for F > (2) 

where A/ is the difference current, n is the free stream plasma density, A is the 
probe area, e is the elementary charge, d is a unit vector normal to the probe, 
V, and Vf are the electron and ion flow velocities respectively, and F is the probe 
potential. If v^ and v^ are known from other data, and analysis of A7 does not 
give agreement, the discrepancies are interpreted as being due to wake associated 
phenomena, or wake effects. The first order results given in equations (1) and 
(2) are also effects of the flow of plasma past the probe, but are not usually described 
as wake effects. 

3. Flight 1 — Black Bkant VB-18 

The first flight of the split Langmuir probe was on a Black Brant VB sounding 
rocket launched from Fort Churchill on 2 August 1968 at a time near local midnight. 
The results of the flight and the details of the instrument have been reported in 
papers I and II. 

The probes on this flight were aquadag coated, flat, circular discs, 8 cm in diam- 
eter and 1 mm in thickness and which were mounted on booms approximately 
^ meter from the rocket body. By comparison at apogee the Debye length was 
1-2 cm, the thermal electron gyroradius was 2-2 cm, and the thermal ion g3a'oradius 



Properties of the wake of small Langmuir probes on sounding rockets 



121 





I I I I I l; l I I I 



2691 

FLIGHT TIME, seC 




i MINIMUM 
} SPINMUI. 




Fig. 1. Three high time resolution, samples of the temperature and density 
measurements deduced from data from the perpendicular detector on the Black 

Brant rocket. 



4 meters. Raw flight data from the perpendicular detector was discussed in papers 
I and II. The superficial discussion of wake phenomena in the two previous papers 
concluded that the raw data indicated that the apparent electron flow velocity, 
as indicated by the difference current at positive potentials, was much larger than 
the apparent ion flow, as indicated by the difference current at negative potentials. 
This anomaly was interpreted as being due to probe wake. It is discussed further 
below. 

As discussed above, the single plate current data can be analyzed to give 
information of plasma temperature and density in the wake of a probe near plasma 
potential. Three examples are shown in Fig. 1 , which shows the sine of the spin 
phase angle, the electron temperature, and the electron density as measured by 
the perpendicular probe. The temperature data shown in Fig. 1 is typical of the 
entire flight in that there is no significant systematic spin variation of the measured 
temperature. The dashed lines indicate the location of the density maxima expected 
from the times of maxima of a sine wave fitted to the ion difference current data. 
Within the errors, there is good agreement between the times of the density maxima 
from the difference current data, and the density maxima in the single plate current 
data. It can be seen from the figure that the lowest apparent density observed 
on a given spin was typically 80-85 per cent of the maximum observed that spin. 
This is interpreted as a decrease in plasma density in the wake of the probe itself. 
This perturbation cannot be due to the vehicle wake because, in such a case, the 
single plate maxima would be 90° out of phase -with the difference current maxima. 
In a situation where vehicle wake is the dominant wake influence in the probe, 
the single plate maxima occur when the probe is farthest from the wake, i.e. when 
the boom is pointing foreward along the velocity vector. On the other hand, the 
difference current maxima still occur when the normal to the plate is most parallel 
to the velocity. It is significant that little apparent change in the perturbation 



122 



E. A. Bebing 



BLACK BRANT 

APPARENT ELECTRON VELOCITY 
ALTITUDE, KILOMETERS 

no 150 200 250 284 250 200 150 110 



O 
Q 



o) 

1 ^ -100 

ir 
o 



-300 
300 



o 

uj a 
> w 

V> 
UJ 

S 






■-V 



100 200 300 400 500 

FLIGHT TIME, seC 

Fig. 2. Apparent electron flow velocity plotted in Earth fixed geomagnetic 

coordinates. These data are believed to be manifestations of the wake, not the 

actual electron flow velocity. 



was observed on the downleg. This implies that the probe was observing only its 
own wake throughout much of the flight. 

The methods of analyzing the difference current data have been discussed in 
paper I. Figure 2 shows the apparent electron flow velocity in geomagnetic coordi- 
nates. As discussed in paper II, the large magnitude of the apparent electron 
velocity was an effect of the wake of the probe. 

This data has a number of features which reveal aspects of the structure of 
the probe wake. The magnitude of the apparent flow velocity varied periodically 
from near zero to a maximum that was typically 10-15 per cent of the electron 
thermal velocity. The period of the variation was the same as the precession period 
of the vehicle, and the magnitude of the apparent flow velocity was a minimum 
at the same time that the angle between the rocket spin axis and the magnetic 
field was its minimum value of 7°. The interpretation of Fig. 2 is that the large 



Properties of the wake of small Langmuir probes on sounding rockets 123 

difference current is due to a density decrease in the wake of the probe. Conse- 
quently, the wake facing side of the probe receives a substantially reduced thermal 
flux of plasma. Since the electron thermal velocity is much larger than the plasma 
bulk flow velocity, the wake effect difference current is much larger than the first 
order linear difference current as given in equation (2). 

Furthermore, it is apparent that the density decrease is a function of rocket 
attitude, and increases as the angle between the rocket spin axis and the magnetic 
field increases. This could be due either to a field aligned wake structure that 
appears in the difference current as the rocket tips over, to a wake increase caused 
by an increase in the projected area of the probe normal to B, or to a combination 
of the two. 

It is also significant that the magnitude of the density decrease at positive 
potential is approximately the same as the decrease observed at plasma potential. 
This indicates that the effect of the probe potential on the structure of the wake 
is relatively small for this geometry. 

An analysis of the difference current data at negative potentials from this 
flight has been reported in paper I. In that paper, a comparison between the 
electric field deduced from the measured ion flux, and the electric field reported 
by Kelley et al. (1971) from a double probe experiment on the same rocket was 
made. The initial comparison showed significant precession periodic discrepancies 
between the two measurements. In order to reduce these discrepancies, a first 
order correction for wake effects was made, as described in paper II. Figure 3 
shows a comparison of the electric field deduced from uncorrected and corrected 
data, and the electric field reported by Kelley et al. (1971). The figure shows 
that a small reduction in the discrepancies has thereby been achieved. This indicates 
that there are basic similarities in the structure of the probe wake at positive and 
negative potentials. The magnitude of the remaining discrepancies argues that 
there are some equally fundamental dissimilarities as well. 

Furthermore, the differences between the two measurements are larger on the 
downleg than on the upleg and are largest near apogee. Since the vehicle wake 
is most likely to influence a fore ward boom mounted probe at apogee, and more 
likely to influence such a probe on downleg than up, this may indicate that the 
major disturbance is due to the vehicle wake, rather than the wake of the probe 
itself. Such an effect would not be reduced by the correction mentioned above, 
which corrects only for the self wake of the probe. This interpretation is supported 
by the observation that the raw difference current data at negative probe potential 
deviates most from sinusoidal at times when the disturbance is maximum. 

The effect of this deviation is further discussed in paper II, where a comparison 
of the electric field results deduced by analyzing data from two different negative 
probe potentials is presented. Paper II shows that there are significant differences 
between the two results, particularly around 260 and 400 sec flight time. They 
were attributed either to the effect of the vehicle wake on probe function, or to 
variations in the field aligned structure in the probe's wake as a function of probe 
potential. 

There were also indications of a substantial space charge in the wake of the 
probe. It was shown in papers I and II that photoemission from the probes during 



124 



E. A. Bebing 



Altitude, km 



2 



y 1- 

li 

<u 







llOlgOZOO 250 


284 250 200 150 110 







, 1, , 1 1 


1 1 1 1 1 '_ 




— 


W*** 


Double Probe 

Split Probe. Corrected 








Split Probe, Uncorrected 




— 




— 




— 


i^nt"^"^ 


j^^j^^ 




— 




|/^J^ = 




— 




- 


WEST 


— 




— 




— 




A"' - 





— 




j^f.^jf^ - 


— 


HyL ^Sf^ 


^Y ~ 


EAST 


— 


1 1 


1 1 



60 
NORTH 



2 



0) 



(U 



o 
- E 

o b 

? 

JZ 



SOUTH 
-60 



100 



200 



300 



400 



500 



plight time, sec 



Fig. 3. Perpendicular electric field components in the Earth fixed geomagnetic 
north and west directions deduced from data taken by the Black Brant payload. 
The figure shows the results of applying a wake effect correction to the split 

Langmuir probe data. 

the flight was reduced by a factor of 30, presumably by wake effects. 

This observation was checked by including the expected photoemissivity in 
the ion flow analysis. The result is shown in Fig. 4. The gross disagreement between 
the deduced electric field shown in the figure and the electric field reported by 
Kelley et al. (1971) and shown above is confirmation that the photoemission 
was in fact substantially reduced. 

Examination of the photoelectron spectrum reported by Hintereggeb (1960) 
indicates that photoemission reduction of the observed magnitude would result 
from a space charge potential of —3-5 volts in the wake. 

4. Javelin 8-56 

The second successful flight of the split Langmuir probe was on a Javelin 
sounding rocket launched on 3 April 1970 from Fort Chiirchill, Manitoba, Canada, 
at a time near local midnight. The probes on this flight were 3 mm diameter 
cylinders. The split section was 9-5 mm long, with a 14 mm long guard cylinder 
at each end driven at the same potential as the detecting hemicylinders. The 
probes were mounted on one meter booms at the nose of the vehicle. 



Properties of the wake of small Langmuir probes on sounding rockets 



126 



a 

UJ 

o 

o <" 
Ui£ 

o\ 
q:> 

I 
I- 
q: 
o 



o 

_] 



o 
(r 

iij-i- 

-I 0). 
Ml 



ALTITUDE, km 

110 150 200 250 284 250 200 150 110 



N 



A 



\^**k 






CORRECTED FOR EXPECTED 
PHOTO CURRENT 



u 



'^ 



200 300 

FLIGHT TIME, sec 



Fig. 4. Perpendicular electric field components in the Earth fixed geomagnetic 

north and west directions deduced from data corrected for photoemission of 

nominal intensity. Data taken by the Black Brant payload. 



On this flight, there was a malfunction somewhere in the payload which had 
the effect of driving the payload potential negative with respect to the plasma. 
As a result, the split Langmuir probe input electronics went out of common mode 
range about 400 sec into the flight. During the period of the flight that good data 
was obtained, the Deb ye length varied from 2 mm to 1 cm, the thermal electron 
gyroradius was about 2 cm and the thermal ion gyroradius about 4 meters. 

The rocket attitude on this flight was exceptionally stable. The precession 
cone half angle was only 2-8°. For the purpose of analysis, it has been assumed 
that a precession cone this small introduces negligible precession dependence in 
the wake. Under this assumption, each density value measured by the perpendicular 
probe at plasma potential has been normalized with respect to the density corre- 
sponding to the maximum flux measured at plasma potential on any sweep during 
that particular spin. The normalized values corresponding to a given number of 
sweeps away from the maximum were then averaged over the entire body of good 
data. A similar analysis has been performed for electron temperature, normalized 



126 



E. A. Bering 



< 



M 



o 

z 



-317 



+211 



211 -106 +106 

SPIN PHASE, DEGREES 

Fig. 5. Normalized, averaged electron temperature measured by the Javelin 

pay load and plotted as a function of spin phase. 

with respect to the temperature measured on the same sweep as the density maxi- 
mum that spin. The results of this analysis are shown in Figs. 5 and 6. The error 
bars shown are the errors in the mean. 

The curve shown in Fig. 5 indicates a slight but significant rise in the temperature 
in the probe wake, on the average. This is consistent with results reported by 




-106 +)06 

SPIN PHASE. DEGREES 

Fig. 6. Normalized averaged electron density measured by the Javelin payload 
and plotted as a function of spin phase. 



Properties of the wake of small Langmuir probes on sounding rockets 127 

Samir and Wrenn (1972). It is interesting that this temperature increase can be 
observed in the wake of an object as small as these probes. 

The curve shown in Fig. 6 indicates an approximately 50 per cent decrease 
in the wake of the probe. This was not expected for a probe this small. One of 
the design hypotheses behind the idea of flying a small probe was the idea that the 
wake of a small probe at plasma potential would be small. A 50 per cent decrease 
in the density of a small probe was unexpectedly large. The result raises a sub- 
stantial question about the absolute accuracy of all spacecraft Langmuir probe 
analyses done under the assumption that small probes mounted well clear of the 
body wake are not significantly afli'ected by their own wake. 

The common mode problem mentioned above made accurate determination 
of the apparent electron velocity impossible, since the common mode problem had 
the effect of truncating and distorting the positive portion of the sweep. As a 
result, accurate determination of the amplitude and phase of the sinusoidal variation 
of the difference current at positive potential was impossible. Hand analysis of 
randomly selected points throughout the flight gave apparent electron flow velocities 
of between 40 and 80 km/sec. This is about 20-40 per cent of the electron thermal 
velocity, and indicates a wake density decrease of the same amount. The reason 
for the apparent reduction in the wake density decrease at positive potential as 
compared to plasma potential is not understood. This apparent reduction in the 
decrease could be a spurious effect introduced by the common mode error instead 
of being a real property of the wake of the probe. In either case, 20-40 per cent 
can be taken as a lower limit on the decrease in plasma density in the rear wake 
of a small cylindrical probe at positive potential. 

In the absence of good data at positive potential, the technique employed in 
the previous section for discussing the properties of the wake at negative potential 
cannot be used. This difficulty is compounded by the fact that the payload's 
electronic maladies had the additional unfortimate effect of introducing substantial 
commutator noise on the high gain difference current channel of the perpendicular 
split probe. As a result, the data had to be averaged over 16 spin periods to produce 
meaningful results. The averaged split probe data and data from a double probe 
experiment on the same rocket (Kelley, private communication), are shown in 
Fig. 7. All that can be deduced from this figure about the wake at negative potential 
is that the density decrease must be much less than 50 per cent probably on the 
order of 10-20 per cent at most. 

5. CONCLTJSIONS 

A new technique for examining the structure of the wake of small Langmuir 
probes on spacecraft has been discussed. The main conclusions that can be drawn 
from this study are : 

(1) Small probes, even probes smaller than the Debye length, do have sub- 
stantial wakes. 

(2) The largest effects of the wake are seen in the electron collection character- 
istics of the probe. Since these rockets were moving slowly compared to the electron 
thermal velocity, the wake is presumed to be primarily due to the interaction of 
the ions with the vehicle. Therefore, the electron wake is due to the effect of local 



128 



E. A. Bbbino 



JAVELIN 8.56 



2 43 348 



100 
75 



UJ <1> 

.-HE 






ALTITUDE, km 

493 535 556 557 

-T^-r, 1 I I I I I I I , .— r r - 



537 496 436 354 251 

-T i 1 I I I I I I I II I I I ' I I 1 I I 



V'lA.-'.' 



.T 



.^• 



..-^' 



•>>/ -^/-f 



^Vm/v'"" 



^..^vV^v'-o;'' 



^vJr.-»7 K.jW^v" 'i''^ \^^f'"\r-;.^' 



-Ni 



• DOUBLE PROBE 
-SPLIT PROBE 



150 200 



' ' .. '.1 J I ' III I ' ' ,1 ' ' ' ' ' ' ' '-' cL' ' ' 'in' ' ' ■'-. 



100 




75 


h. 




O 


bO 


rr >- 


25 





•25 




-■in 


tcF 






-75 


-i 




X 


-ion 


h- 








o 



"250 300 350 TOO 450 500 650 600 650 700 

FLIGHT TIME, sec 



Fig. 7. Perpendicular electric field components in the Earth fixed geomagnetic 
north and west directions measured by two experiments on the Javelin payload. 

electric fields. This implies that any accurate wake model must include electric 
field terms. 

(3) The wakes of small probes show apparent magnetic field aligned structure. 
This is an unexpected result, considering the large ratio of ion gyroradius to probe 
radius. This result places further restraints on allowed model approximations. 

(4) The observation that small probes do have substantial self wakes calls 
into question one of the key assumptions used in analyzing spacecraft Langmuir 
probe data. This is the assumption that small, boom mounted probes do not suifer 
from selfwake problems. 

(5) Space charge potentials in wakes can be large enough to substantially 
alter photoemission. 

Acknowledgements — The author wishes to thank Professor F. S. Mozee for his many helpful 
comments and ideas, and for reviewing the manuscript. He also wishes to thank Dr. M. C. 
Kelley for helpful comments and the double probe electric field data, and Dr. U. V. Fahleson 
for helpful comments. Finally, he also wishes to thank Dr. A. Kavadas, Mr. M. Hodson, 
Mr. N. FouLDS and the Space Engineering Division of the University of Saskatchewan, Canada, 
for the assistance they provided during the Black Brant program. 

The instrument development and data analysis required for these programs were supported 
by the Atmospheric Sciences Section of the National Science Foundation under grants 
GA-918 and GA-1317, by the National Aeronautics and Space Administration under grants 
NGR 05-003-239 and NGR 05-003-445 and in part by a contribution from the National Research 
Council of Sweden. Space was provided on the Black Brant by the National Research Council 
of Canada. 



Bering E., Kelley M. C. and Mozer 

F. S. 
Bering E., Kelley M. C, Mozer 

F. S. and Fahleson U. V. 



References 

1973a J. geophys. Res. 78, 2201. 
1973b Planet. Space Sci. 21, 1983. 



Properties of the wake of small Langmuir probes on sounding rockets 



129 



BOGASHCHENKO I. A., GuBEVICH A. V., 

Saiimov R. a. and Eidelman Yu. I. 
BouBDEAtr R. E. and Donley J. L. 
Brace L. H., Cabignak C. R. and 

FiNDLAY J. H. 

FiKDLAY J. a. and Bbace L. H. 
Gtjbevich a. v., Pitaevskii L. P. and 

Smibnova V. V. 
Hendebson C. L. and Samib U. 

HiNTEBEGGER H. E. 

Kelley M. C Mozeb F. S. and 

Fahleson U. V. 
Lir V. C. 

MiLLEB N. J. 

OyaH. 

Samir U. 

Samir U. and Wiixmobe A. P. 

Samib U. and Jew H. 

Samir U., Maier E. J. and Troy 

B. E., Jr. 
Samib U. and Wbenn G. L. 
Samib U. and Wbenn G. L. 
Wrenn G. L. 



1971 Sov. Phys. JETP 32, 841. 

1965 Proc. B. Soc. A281, 285. 

1971 Space Research XI, p. 1079. Akademie 

Verlag, Berlin. 

1969 Proc. IEEE 67, 1054. 

1969 Space Sci. Rev. 9, 805. 

1967 Planet.SpaceSci. 15, 14:59. 

1960 Space Research I, p. 304. North-Holland, 
Amsterdam. 

1971 J. geophys. Ees. 76, 6054. 

1969 Space Sci. Bev. 9, 423. 

1972 J. geophys. Bes. 77, 2851. 

1970 Planet.SpaceSci. 18, 793. 
1970 J. geophys. Bes. 75, 845. 
1965 Planet. Space Sci. 13, 285. 

1972 J. geophys. Bes. 77, 6819. 

1973 J. atmos. terr. Phys. 35, 513. 

1969 Planet. Space Sci. 17,693. 

1972 Planet. Space Sci. 20, 899. 

1969 Proc. IEEE 57, 1072. 




^ 



Hit T 
5 i i i i 



Finite Heat Conduction Effects On 
Ion Cyclotron and Drift Cyclotron Modes 



Mary K. Hudson 



Space Sciences Laboratory 
University of California 
Berkeley, California 94720 



January 1975 



Abstract 



Finite heat conduction effects on the ion cyclotron and drift cyclotron 
instabilities are investigated, along with the converse effect of these 
modes on electron thermal conductivity. 



Introduction 

Recent Q machine experiments have demonstrated that the high frequency 

1 2 

electrostatic ion cyclotron (IC) and ion cyclotron drift (ICD) instabilities 

generate anomalous resistivity which inhibits the destabilizing current when 

the plasma is stable to the ion acoustic mode; apparently the low frequency 

3 4 
drift instability does not . Finite heat conduction affects on the ion 

c fi 7 ft 

acoustic and drift ' * modes have been investigated and shown to be desta- 
bilizing in certain regions of parameter space. It is the purpose of this 
paper to analyze the effect of finite electron thermal conductivity on the 
IC and ICD modes. Electron thermal conductivity along a z-directed magnetic 
field is reduced by collisions at parallel wavelengths exceeding the electron 
mean free path k X <1. In a turbulent plasma the wave-particle interactions 

Z 6 

which produce anomalous resistivity can either increase or decrease the ther- 

9 

mal conductivity, depending on the mode which is generating the turbulence. 

After treating the effects of finite electron heat conduction on the linear 
IC and ICD modes, we will consider the influence of these modes on anomalous 
thermal conductivity. 

Linear Dispersion Relation 

Hendel and Yamada have derived the linear dispersion relation for the IC 

and ICD modes in a fully ionized, collisionless, inhomogeneous plasma from 

the Vlasov equation. In these modes with k ./k, «1, the electrons move primarily 

parallel and the ions perpendicular to the magnetic field. Collisions should 

be included in the electron contribution X to the dielectric function 

e 



e = 1 + Xj + X fo^ k X <1, realized in some experiments. The ions remain 

collisionless for k p.il and p,/X <<1, where p. is the ion Larmor radius. 

11 1 e 1 

To include collisions, and in particular finite electron thermal conductivity, 

we compute x from the electron fluid equations of continuity, momentum and 

heat transfer in the ion frame, which are valid for k X <1 

z e 

3n/3t + V • (nv) =0 (1) 

mn(dv/dt) = -V(nT^) - ne[E + (v/c) x B] - C nVT + R . (2) 



3/2 n(dT /dt) + nT V'V = -V-q + Q (3) 

e e — 

R J = -C Dm\> v (4a) 

ei r e- 

The coefficients C =0.51, C =0.71, and C =3.16. The parallel electron heat 

r ' t X '^ ' 

flux is 

q = C^nT V - C (nT /mv )VT (4b) 

-^ tez xe e e 

The collisional energy transfer from electrons to ions is given by 

Q = -3(m/M)nv (T - T.) (4c) 

eel 

Both depend on the electron-ion collision frequency v . 

We neglect electron inertia at low frequencies ((A)<<a) ) , and treat the 
perpendicular electron motion in the guiding center approximation for k^/k >>1. 
Retaining the collisionless Vlasov result for x , the dispersion relation 
becomes 

e = l + x+X^=0 ^^^^ 



8 



x^ = 



-_^ 



2 2 



0) - Vjj 



U) 



- nfi 



k a. 
z 1 



, , /— oj-nfl / (o)- 

1 - i/ir -^j exp I- -^^ 

\ k a. 
z 1 



?1 



0). 



j(a)-c|! 0),) + iv„ (oH-X^jj+C^o),) - vlijJZ) 



k^X^ a)(a)-C|:a), ) + iv„ [a>(l+x) + 1/3 C^u,] - v,^(Y-"D + to? 



Here u^/k ■ (cT /eB)V(ln n) is the electron dlainagnetic drift in an 
D y e 

x-directed density gradient, ui, /k = V is the current-driven electron drift, 

and v„ = k a /v is the parallel electron heat conduction rate. T = I (b)e 
"zee n n _ 

where b =■ ki%^/2fi ^; C^ = (1 + C^) , Cj; = (2 + C^), f = 2/3 Kv^l+C^)^] , 

I = 2/3 (1 + C^)^ and R^ = T^/T^ is the 

ion-electron temperature ratio. Other standard notation includes the elec- 
tron and ion thermal speeds a and a. , ion cyclotron frequency ^ and electron 
Debye length X . We have expanded the ion Z-function in (5a) for large 

argument (w - nil) /V. a. >>1 and henceforth assume kA_<<l for the modes of 

z i ' D 

interest. 

We will compare the fluid electron dielectric in (5a) with the colli- 

2 
sionless Vlasov result 



^e 2 

® k^A 



b( 



a)-k V- 
1 + i A - ^ 



: e J 



(5b) 



Here the electron Z-function has been expanded in the small argument limit 

for (u) - k V)/k a «1. 
z z e 



Marginal Stability 



At marginal stability we can set the real and imaginary parts of (5a) 
separately equal to zero and solve the real part for the frequency at the 
n » 1 harmonic 



0) = n 



1 + 



r, (b)(i-R^a)jj/n) 



0) fi-v (Y-T)l 



n(i+A) 



(6a) 



tfi -v.f (Y-DJ 

11 2 

where G(b) s F + (1 - F )/b. The isothermal result is recovered 
1 o 



as v„ (Y-f) ■* " (v^^). For Wp<J2(>Q) the parameter A is increased (decreased) 
by the finite heat conduction terms. This corresponds to an increase (decrease) 
in the marginally stable electron drift obtained from the imaginary part 

t 

of (5a), assuming v,^»bi, oi and neglecting ion Landau damping for (ui-nil) /k' a^»l^^ 

■^ z i 



\\-l )(Tf% vji 



2/3 <l-^^t^ 



7^ (Y-I) k,x^ 

z e 



(6b) 



In contrast to (6b) , the collisionless kinetic threshold electron drift 

2 
obtained by substituting (5b) for x in (5a) is 



V 
— > 

a 

e 



k a I 
< z e/ 



(6c) 



The combined threshold is 



1 Jr^\U^ 1 ^j^ 



k X 
z e. 



1 + 



2/3 <^^^t> 

(x-D 



k X 
z e. 



(6d) 



We have included both fluid and resonant destabilization in (6d) . The 

two are derived separately for fluid and Vlasov electrons, respectively, and 

only one applies in a given limit of k X . However, this is accounted for 

in (6d) since the fluid result dominates for k X <<1. In the limit k X «1, 

z e z e * 

(6d) demonstrates that finite electron thermal conductivity (Y) is required 



to couple the destabilizing current to the IC mode, just as it is for the 
colllsional, current driven ion acoustic and drift modes. Thus, while the 
threshold drift is increased by about a factor of two or over the collision- 
less limit, it is finite heat conduction that enables the IC mode to persist 
in the collisional case. 

For a)_>a), the current threshold in (6d) vanishes, and (6a) yields the 

nonresonant ICD mode destabilized directly by the density gradient. The 

» 

instability threshold, a)_>aj, is reduced as A is reduced by finite heat con- 
duction for t«>Tj>fi in (6a). While the IC mode is a current driven instability 
with drift correctioiB in an inhomogeneous plasma, the ICD mode is destabi- 
lized directly by the density gradient for scale lengths the order of the 
ion Larmor radius. This latter mode persists in the collisional limit, 

even for infinite thermal conductivity (x •* ~ in 6d) . Likewise, the col- 

fi 7 fi "5 

lisional drift * ' and ion acoustic modes have non-current driven branches 

which persist in the isothermal approximation. 

A further comparison can be made with finite heat conduction effects 

on the collisional drift mode destabilized by the ion finite Larmor radius 

6 7 8 8 

drift in the absence of a parallel current ' ' . Hudson and Kennel have 

shown that finite heat conduction increases (decreases) the drift instabi- 

14 
lity threshold when ki /k is small (large) . Likewise, the fastest grow- 

ing IC mode has k^/k 'vlO, and the threshold is increased by finite heat 

conduction. However, the fastest growing ICD mode has k^/k >>10, and the 

threshold is decreased. Finite parallel electron thermal conductivity 

appears to enhance strongly field alligned modes (k. /k >>1) . 



Nonlinear Effects 



Electrical and thermal conductivity are finite to the same order of 
approximation in the fluid equations (1-3) which are moments of the Vlasov 
equation below. In a turbulent plasma the wave-particle interactions which 

produce anomalous resistivity can either increase or decrease the thermal 

9 
conductivity, depending on the mode which is generating the turbulence . 

9 
Caponi and Krall investigated the effect on parallel electron 

thermal conductivity of modes with k /k,<<l destabilized by a perpendicular 

current. Their procedure was to take moments of the Vlasov equation, assum- 



ing a quasllinear form for the nonlinear term on the right hand side 



12 



3t — 3x m 3v 



f(x.v.t) - ^|-<Ef> 



m dv 



(7) 



where E and f are the perturbed electric field and particle distribution 
function. 

While the k spectrum is 3-dimensional, only spatial variation and heat 

flow in the z-dlrection are considered. The electron distribution function 

2 2 

is assumed to be quasimaxwellian, f = f (z, ( v - V ) , t) + f. (ZfV , (v-V) jt), 

yielding a complete set of three equations in v , nT and the random heat 

z z 

flux Q = m/2/dv v f , . The set is reduced to two equations by assuming 
z J z 1 

e i 
ambipolarity, 9/9t(v - v ) = 0. The equation governing the anomalous 

z z 

thermal conductivity on the right hand side 



3Q _ T 8T 
z 3^ _z z 

9t 2 " m 3Z 




m 



3q|dk E^ k^|dv(v/- ijlme^^^ (8) 



Is solved simultaneously with a heat transfer equation like (3), which now 

includes a turbulent heating term. Here the electric field energy density 

2y t 13 

obeys ^(t) = E, e k , where e, is? the thermal noise level and the 

growth rate y, is determined by the linear dielectric function e, = j dv e. 

Of the three modes which they investigated (Buneman, modified two- 

2 
stream and ion acoustic) only the nonresonant Buneman satisfied v > T /m 

or oj/k a > 1 in (8) , leading to a negative anomalous thermal conductivity 

or enhanced heat loss. Physically, the Buneman mode propages along the 

magnetic field faster than electrons, and conducts energy away faster. We, 

therefore, expect other nonresonant modes like the ICD, which has (o/k a >>1, 

to increase electron thermal conductivity. On the other hand, finite heat 

conduction effects on the resonant IC mode, which has w/k a <<1, should be 

• z e 

more pronounced.. Evaluation of the anomalous thermal conductivity matrix 
element for the case of a parallel current, which destabilizes the IC mode, 
and a perpendicular density gradient, which destabilizes the ICD mode, will 
be presented elsewhere. 



Summary 

In conclusion, we have investigated the effects of finite parallel 
electron thermal conductivity on the current (IC) and density gradient (ICD) 
driven Ion cyclotron modes. We have found that finite heat conduction in- 
creases the IC threshold and decreases the ICD threshold. The nonlinear 
effect of these modes on thermal conductivity tends toward stability, as 
one would expect. From physical arguments it follows that the nonlinear IC 
mode decreases while the ICD mode increases parallel electron heat loss. 
The latter effect may limit ion heating ' if a local nonlinear mechanism 
exists which transfers perpendicular ion to parallel electron energy. 



References 

Benford, G., N. Rynn, J.J. Thompson and W.S. Williamson, Phys. Fluids 17 , 
101, 1974. 

Hendel, H.W. and M. Yamada, Phys. Rev. Lett., 22, 1076, 1974. 

3 
Coppi, B. and E. Mazzucato, Phys. Fluids, 14, 134, 1971. 

4 
Hendel, H.W. and M. Yamada, private communication, 1974. 

Rognlien, T.D. and S.A. Self, Phys. P^ev. Lett., _27, 792, 1971. 

Tsai, T.S., F.W. Perkins and T.H. Stix, Phys. Fluids, 13, 2108, 1970. 

^Ellis, R.F. and R.W. Motley, Phys. Fluids, 17, 582, 1974. 

g 
Hudson, M.K. and C.F. Kennel, submitted to J. Plasma Phys., 1974. 

9 
Caponi, M.Z, and N.A. Krall, Bull. Am. Phys. Soc, 19, 925, 1974. 

Braginskii, S.I., Reviews of Plasma Physics , I, M.A. Leontovitch ed.. 
Consultants Bureau, New York, 205, 1965. 

"""■hcindel, J.M. and C.F. Kennel, J. Geophys. Res., 68, 2579, 1963. 
12, 



Liewer, P.C. and N.A. Krall, Phys. Fluids, 16, 1953, 1974. 

LI, N.A. and A.W. Trivelpiece, 
New York, Ch. 8 and 11, 1973. 



13 

Krall, N.A. and A.W. Trivelpiece, Principles of Plasma Physics , McFraw-Hill 



The drift instability threshold is increased (decreased) by finite heat 



conduction for k./k « /v^ /v„ < /^Tl (>/o7r ) where v^= 0.3b/m/2Mv is the 

perpendicular ion diffusion rate. 

Palmadesso, P.J», T.P. Coffey, S.L. Ossakow and K. Papadopoulos , Geophys. 
Res. Lett., 1, 105, 1974. 



Ion Landau damping adds a term r r, (b) exp [- ^ ^^ ^ g 

hand side of (6b)-(6d). z^i \ z ^i / 



16^ , _ ,, , . ,_ „„, , 

" to the right 

(6b)-(6d) 



10 



The author gratefully acknowledges helpful discussions with Drs. 
G. Benford, C. Kennel, N. Krall and M. Yamada. This work was supported 
under NOAA Grant No. 04-5-002-16. 



Submitted to Astrophys. J. (1975) 



^ 



TOWARDS DIFFRACTION-LIMITED SEEING OF DIM ASTRONOMICAL [h 
OBJECTS FROM THE EARTH'S SURFACE USING LIDAR 

Brian G. Cartwright and Ashok J. Gadgil 

Department of Physics, University of California, 
Berkeley, California 94720 

Received 




ABSTRACT 

It is proposed that LIDAR probing of the atmosphere coupled 
with active optics be used to eliminate the image-degrading effects 
of turbulence lying within the bottom few kilometers of the atmos- 
phere above large astronomical telescopes. Available evidence, 
although scanty, suggests that resolution near the diffraction limit 
may be possible under some atmospheric conditions at many observa- 
tories, and that considerable improvement in resolution would almost 
always result. |f, as is believed likely, image-degrading turbulence 
at altitudes greater than a few kilometers is confined to a thin layer 
at the tropopause, a more complex two-pulse, two-correct ion- plane 
system can be used to eliminate the residual effects of this layer, 
thereby providing diffraction-limited seeing over a f ield-of-view as 
great as several arc minutes or more for observing any object, no 
matter how dim. 



I. INTRODUCTION 

Since the time of Galileo, the resolution of astronomical 
telescopes has been limited by turbulence-i nduced spatial and temporal 
fluctuations of the atmospheric index of refraction, rather than by 
diffraction at the telescope aperture. The instantaneous image of 
a point source at infinity obtained by a telescope with an aperture 
larger than about 10 cm is a speckle pattern arising from multiple- 
beam interference of the portions of the Incoming wave which have 
traversed different optical path lengths through the atmosphere. On 
nights of good "seeing" (low image degradation) , identical specl<le 
patterns are obtained when one looks at the same point source with 
the center of one's aperture situated anywhere within a region of about 
10 cm diameter, or when one looks at point sources within about 
10 yrad of one another. The pattern relaxes within about 10 msec. 
Systems which can actively correct for atmospheric distortion by 
analyzing the image obtained from an astronomical object are now be- 
ing developed by several groups (Muller and Buffington IS?'*; Felnlelb 
et al. 197^ and Hardy et al. IS?'*; Bridges 1974). Diffraction-limited 
performance through the atmosphere over 10 yrad f lelds-of-vlew may be 
obtainable soon for sufficiently bright objects. 

Here we propose a technique which may make possible extension of 
these new methods to dim astronomical objects: the use of LIDAR (Laser 
radar) echoes as an on-line probe of atmospheric conditions. 

II. ACTIVE-PUPIL SYSTEMS 

Turbulence-compensating systems can be understood by regarding the 
Image aberration as resulting from the effect of an aberration function 



-2- 



(phase-shift as a function of position) expressed at one of the optical 
elements of the telescope, all other optical elements and the air- 
column being regarded as free of aberration. If this equivalent aber- 
ration is detected and if the optical element is "corrected" by suitable 
mechanical deformation, the aberration may be removed. 

Two ways to detect aberration have been proposed to date: shearing 
interferometric detection (Feinleib et al . IS?'*) and sharpness-function 
detection (Muller and Buffington ig?'*). An interferometric detection 
scheme which has occurred to us, and which appears very well suited for 
the system proposed in this paper, in that a single image contains all 
the information required for correction, is achieved by imaging the 
deformable optical element through a phase-contrast telescope, operating on 
the same principles as a phase-contrast microscope. (We have learned pri- 
vately that R. H. Dicke has also suggested a phase-contrast scheme). 

Any scheme using the incoming photons from the astronomical object 

under observation to measure the aberration function will be limited 
by photon noise. The aberration function for the atmosphere is known 
to be band-limited in spatial frequency, so the Whi ttaker-Shannon 
sampling theorem is applicable. For an aberration function with a 
maximum wave number of 2Tr/10 cm"^, one needs at least 0.2 samples cm~^ 
of aperture area. An object of visual magnitude m = 12 viewed in a 
3000 A bandpass through an ideal telescope of 100% optical efficiency 
and 20% photoelectric efficiency produces in 10 msec less than one 
photoelectron per 5 cm^ aperture. Clearly such a weak signal cannot 
be used to correct for image degradation if the character of that de- 
gradation is changing every 10 msec. Thus, m = 12 is the upper limit 

on the sensitivity of unaided, active-pupil devices. 

Range-gated LIDAR can be used to create a light source at high 

-3- 



altitudes. This light source can then be used to illuminate a phase- 
contrast telescope. The aberration function observed by the phase- 
contrast telescope then corrects the astronomical image. 
Note that, as in phase-contrast microscopy, where wide-angle reflected 
skylight is sometimes used as a light source (Bennett 1951), this 
light source need not be coherent, but must subtend an angle smaller 
than an isoplanatic patch (about 10 yrad) , an angle which is much 
larger than the Airy resolving power of a large astronomical telescope 
(about 0.1 yrad). Since we were unable to find a scattering process 
more effective for the present purposes than Rayleigh scattering, in 
the following we consider only LIDAR from Rayleigh backscatter. 

To calculate the intensity of back-scattered light we have used 
Rayleigh-scatter ing and atmospheric attenuation data (Valley 1965) at 
3800 A and 7000 A to estimate the number of photoelectrons resulting from 
backscattering into a 10-cm diameter area (one isoplanatic patch) per 
joule of laser energy for a 1 km range-gated slice of atmosphere. Over- 
all efficiency has been assumed to be 0.005 photoelectrons per photon. 
The results are shown in Fig. 1. For comparison we note that an exist- 
ing LIDAR system (Hake et al. 1972) produces about 5 counts at 589O % 
per Joule of laser power into a lO-cm diameter receiver from a slice of 
atmosphere 1-km thick at 20 km. Backscatter intensity as a function of 
angle from the initial beam direction is shown in Fig. 2, under the 
assumption of an exponential atmosphere with a scale height of 8 km and a 
diffraction-limited 10-cm aperture focused at 20 km as a transmitter. 
Since 10 cm is the size of an isoplanatic region^we might expect the 
focal point of any aperture larger than 10 cm to be blurred at least as 



■k- 



badly as a dif fraction- 1 imi ted 10 cm aperture. The range gate must not 
be open very long if the echo light source is not to be blurred much 
beyond the angular extent of an isoplanatic patch. A 1 km slice seems 
about maximum. For laser pulse repetition rates which are high enough 
for many laser pulses to occur within the time the atmosphere changes 
significantly it would be possible to correct the upgoing laser pulse 
as well. In this case the focused spot could be diffraction-limited. 
However, at the present time sufficiently powerful lasers with the 
approximately kHz repetition rates required are not readily available. 
III. ECHO ALTITUDE REQUIREMENTS 
Since the astronomical object of Interest is effectively infinitely 
distant, the light path from the echo signal will more closely approxi- 
mate the light path from the astronomical object if the echo is re- 
ceived from as high an altitude as possible. Fig. 3 shows what happens 
if the turbulence extends over a depth t. If the aperture of the re- 
ceiver has radius R and the backscattering center is at height H, then 
the requirement that the backscatter should pass through the same optical 
path as the light from the astronomical object leads to the requirement 

that the turbulence layer be thinner than 

. . u 10 cm 

^ ^ "~r" (1) 

This is a serious limitation, since within the power limitations 
of contemporary lasers one cannot hope to achieve correction for tur- 
bulence at the tropopause, except by rather costly means, e.g., by 
observing for a fraction of an hour following a rocket-borne sodium 
vapor release at high altitudes in the desired part of the sky. On the 
other hand, often seeing may be primarily due to low-lying turbulence. 



-5- 



I. S. Bowen (quoted by Meinel I960) conducted a qualitative study of 
the seeing at the 60-inch telescope at Mt. Wilson using Schlieren Icnife 
edges to examine double star images. He concluded: "...most of the 
disturbance to the seeing came from layers within 200 meters of the 
telescope." Young (197^) summarized the available evidence: "Townsend 
(1965) ...concluded that two layers with similar temperature fluctuations 
could explain the observations; his upper layer was near 8 km and ~100-m 
thick, while the lower layer was the bottom 1 km of atmosphere . . . 
the upper . . . contributes very little to the seeing. Young (I969) 
fitted scintillation data with two exponential distributions, one with 
a scale height of about 8 km and the other with about 1/2 - 1 km scale 
height but 10-20 times larger temperature fluctuations. Again, the 
lower layer contributes some 90 percent of the seeing . . ." 

Finally, the best guess at present is that image degradation due to 
turbulence at altitudes above the boundary layer Is generally a result 
of wind shear occurring in a very thin sheet at the tropopause (about 
10 km). If this is In fact so, a twin-pulse, two-level correction scheme 
may be applied: first, a laser pulse Is emitted and its echo Is studied 
to determine the aberration resulting from the complex boundary layer 
of turbulence extending for about 1 kilometer above the telescope aper- 
ture. The appropriate correction Is then applied to the optics to remove 
this low-lying seeing. Next, In a time much shorter than 10 msec, a 
second pulse Is emitted, perhaps through optics which also corrects the 
transmitter for boundary layer turbulence, to probe the structure of 
the single thin layer at the tropopause. Under the assumption that this 
layer Is thin the argument summarized by equation (1) must be modified. 



-6- 



since a single thin layer of turbulence can be removed by a second 
correction system located at a position relative to the focal plane 
appropriate to the altitude of the disturbing layer. Thus, one constructs 
an optical correction scheme approximately conjugate to the atmosphere 
(to be truly conjugate a large number of correction planes in one-to-one 
relation to each disturbed layer of the atmosphere would be required). 
Note that this system would be isoplanatic over the isoplanatic angle 
associated with the boundary- layer seeing, which is undoubtedly much 
larger than the observed isoplanatic angle, due to the proximity of the 
boundary layer to the telescope. Such a system would make possible 
diffraction-limited seeing over at least several minutes of arc. 

IV. CONCLUSION 
The altitude structure of the turbulence which produces seeing over 
observatory sites must be studied before the extent of the contribution 
of the bottom layer of the atmosphere to seeing can be determined. There 
is considerable evidence to suggest that by eliminating the effects of 
this layer an order-of-magni tude improvement In resolution may be possible. 
If turbulence arising from altitudes above the boundary layer Is confined 
to a thin layer at the tropopause, the residual image degradation result- 
ing from this thin layer can also be removed. Therefore, we believe 
range-gated LIDAR promises to make possible diffraction-limited seeing 
from large, ground-based, astronomical telescopes. 



-7- 



REFERENCES 

Bennett, A. H. 1951* Phase Microscopy, Principles and Applications 
(New York: Wiley). 

Bridges, W. IS?** (private communication). 

Feinleib, J. ]37k. Laser Focus , JO, kk. 

Hake, R. D. , Arnold, D. E. , Jackson, D. W. , Evans, W. E., Ficklin, B. P., 

and Long, R. A. 1972, J. Geophys. Res ., 77, 6839- 
Hardy, J. W. , Feinleib, J., and Wayant, J. C. 197'*. presented at the 

"Topical Meeting on Optical Propagation through Turbulence" of the 

Optical Society of America, 197't July 9-11, Boulder, Colorado. 
Meinel, A. B. I960, Telescopes , ed. G. P. Kuiper (Chicago: University 

of Chicago Press), p. 159. 

Muller, R. A. and Buffington, A. 1974, J. Opt. Soc. Am. , 64 , 1200. 



Valley, S. L. 1965, Handbook of Geophysics and Space Environments 

(New York: McGraw-Hill), p. 7-20. 
Young, A.T. 1974, Ap. J ., 189 , 587. 



FIGURE CAPTIONS 

Figure I. Calculated numbers of counts recorded by a lO-cm diameter 

LIDAR receiver of efficiency 0.005 photoelectrons per photon 
resulting from 10- Joule pulses at 38OO A (broken line) and 
at 7000 A (solid line), as a function of echo altitude. 
The receiver is assumed to be range-gated so as to receive 
backscattered light from only a 1-km slice of atmosphere at 
the indicated altitude. 

Figure 2. Calculated fraction of the backscattered light contained 

within a given angular radius as a function of that radius 
for a range-gated LIDAR focused at 20-km altitude and gated 
open to receive signals from slices of atmosphere of various 
thicknesses. A diffraction-limited LIDAR transmitter of 
10-cm aperture (solid lines) or 500-cm aperture (broken 
1 ine) is assumed. 

Figure 3* Schematic comparison of the paths followed by light from a 
LIDAR focused at a height H and by light from a star at in- 
finity. A region of turbulence of thickness t overlies a 
receiver of aperture 2R. 



J 



PHOTOELECTRONS 



m 
o 

o 

> 
r~ 

H 



o 
m 

3 



^^. 



O 



O 




CD 

C 



. > 



'^- > 
o 

c 

CO 



f 



ZD (J) - 




) 



STARLIGHT 



LIDAR 
ECHO 




Figure 3