JPRS ID: 9931 USSR REPORT AGRICULTURE

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JPRS L/ 10189
15 December 1981
USSR Report
PHYSICS AND MATHEMATICS
(FOUO 11/81)
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JPRS L/10189
15 December 1981
USSR REPORT
PHYSICS AND MATHEMATICS
(FOUO 11/81)
CONTENTS
FLUID DYNA.MICS
Synthesizing Method of Calculatiag Planar Boundary Layer in
Weak Polymer Solutions With Laminarg Transitional and
Turbulent Flow Zone 1
Laminar Boundary Layer and Its Stability in Weak Polymer
Solutions 9
Wall Turbulence in Weak Polymer Solutions....................... 13
Viscous Drag of 'Ifao-Dimensional Foils Moving in Weak Polymer
Solution...................................................... 23
LASERS AND MASERS
Electric Power Supplies for Lasers 31
- Tunable Lasers 36
('haracteristics of Gasdynamic Lasers Using Combustion Products
With Unstable Cavities 41
Characteristic Features of Driven Amplification of Free-
Runninp Photo-Dissociaticn Iodine Laser Pulses:
Duraticn Control........................ 46
Characteristics of Explosion Gas Dynamic Laser Utilizing
- Acetylene Combustion Products 56
Atmospheric Air Breakdown by Neodymium Laser Emiasion for Large
Focal Point Diameters ..o....................... 69
- a- [III - USSR - 21H S&T FOUO]
FnR nF1F1('TAL USF nNl.ti'
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In Memory of Eduard Sergeyevich Voronin......................... 73
Closed-Cyclp ''ast--Flow Pulsed C02 Laser With Carbon Dioxide
RecovQry Unit 75
NUCLEAR PHYSICS
Diffraction Methods in Neutron Physics 80
OPTICS AND SPECTROSCOPY
_ Use of Degenerate Parametric Processes for Wave Front Correction
(Survey) 84
Pulsed X-Ray Technology 107
Study of Wide-Aperture Flat Resonator Fields 120
Selfimaging Fields.............................................. 129
PLASMA PHYSICS
High-Temperature Plasma Diagnosis Methods....................... 142
MATHEyfATICS
Method of Collective Recognition...... 145
- b -
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FLUID DYNAMICS
UDC 532.526.3
SYNTHESIZING METHOD OF CALCULATING PLANAR BOUNDARY LAYER IN WEAK POLYMER SOLUTIONS
WITH LAMINAR, TctANS1TIONAL AND TURBULENT FLOW ZONES
^toscow I7_VESTIYA AKADFrMII NAUK SSSR: MEKHANIKA ZHIDKOSTI I GAZA in Russian No 33,
May-Jun 77 (manuscript received 10 Jun 76) pp 42-48
(Article hy V. V. Droblenkov and G. I. Kanevskiy, Leningrad)
[Text] Investigation of the influence of small polymer additives
on flow ciiaracteristics of viscous fluid is currently one of
the most promising areas of research on friction drag reduction.
One of the interesting problems here is the study of the influ-
- ence that small pol,,mer additives have on characr_eristics of
tlie transition region of flow in the boundary layer, as well
as on friction drag in the case of laminar, turbulent and tran-
sitional sections in the boundary layer. This article gives
a possible method of calculating the planar boundary layer and
friction drag for the case of motion of a solid in weak polymer
solution3 with constant concentration with consideration of the
cYianRe i.n flow conditions in the layer, based on the use of inte-
gral relati.ons. Problems associated with development of the
boundary layer on the body as the polymer is fed in, and problems
involvinK the influence of degradation or destruction of the
polymer in the solution are not considered.
1. The laminar boundary layer is calculated by Pohlhausen's method with approxi-
matiun uf the velocity proflle by a sixth-degree polynomial [Ref. 1], assuming
that small polym2r additives liave practically no effect on its development. This
assumption is conCirmed by data of experiments done in tubes [Ref. 21. In calcu-
latinti; the laminar botm dary layer, the equation of momenta is integrated, the ini-
tial d TpUMp' the output pawer de-
creased in practice to zero. The energy measurements show, therefore, that the
inversion relaxation in the absence of emission is a comparatively slow process,
with a characteristic time of Z0.1 millisecond. Here the effect of attenuation of
the crailing part of the input pulse is manif ested, which is expressed in the re-
corded energy eqUal i ty in the presence of amplifi.cation at the front.
One of the causes of attenuation of the input pulae in the postamplif ication stage
can be distributed linear losses on inhomogeneities in Xhe active medium of the
amplifier. The source of such inhomogeneities in the iodine system basically is
the dynamic disturbance waves arising during pumping and leading to random defor-
mations of the index of refraction of the medium [5, 6]. Actually, measure-
ments of the radiation pattern demonstrated that the active medium of the ampli-
fier is a complex dynamic lens sharply deforming the initial wave front. Depend-
ing on the delay time, the shape of the radiation pattexn of the amplified emis-
5ion, reflecting in practice the instantaneous pattern of the inhomogeneities,
varic,d significant ly, now acquiring the form of continuous distribution, nuw the form of
49
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distribution with sharp maximum or minimum at the center. This indicates discon-
tinuities in the radial distribtuion of the index of refraction gradient during
collapse of the compressfon waves which is very intense under the cavity tube pump-
ing conditions. I n t h i s c a s e t h e p a t t e r n w i d t h increased from -l to -10
mrad, but by estimates this is insufficient for tlte observed signal attenuation.
The upper bound of the signal attenuation as a result of emission at inhomogenei-
ties of the medium was determined by direct experimentation. For this purpose the
amplifier was filled with a mixture of C F I( at ordinary experimental pressures)
with air. As a result of collision queXging of the excited iodine atoms by
oxygen molecules, the system was converted to the absorbing state. Additional
amounts of an inert gas (Ar, Xe) or C02, SF6, air to a total pressure of 200-600
mm Hg lowered the absorption cross section so much that the active medium became
optically traiisparent on the transition frequency F a 3 to F' = 4. However, as is
known [6], witti an increase in the gas pressure the inhomogeneities do not decrease,
but, on the contrary, increase. Under these conditions, for different pumping levels
of tlie ampli.f ier ttie relative reduction in the laser pulse power on passage through
an opticdlly inhomogeneous medium of a pumped amplif ier did not exceed 10% together
with the residual absorption. Thus, the radiation attenuation in the postamplifying
stage is explained not by the losses ar the inhomogeneities, but by absorption.
For acialysis of the possible causes of transition of the active medium of the ampli-
fier to the absorbing state let us consider the basic processes developed in an
iodine system in the photolysis and postphotolysis stages:
RJ-F-hv� a R+J`:
R-I--R-- (2)
RJ r= R+J; (3)
J'-F-hv b) J+2hv,; (4)
J+ J~-M-� J :+M; (5)
J`+Jz- J+J2. (6)
Key: a. pump b. 1
The radicals R= C3 F7 and their complexes R2 = C6F14 formed under the effect of the
pumpinb libht hvll do not have absorption bands on the lasing frequency vl [7],
:iiiJ therefore ttiey caiinot lead to radiation absorption. Consequently, it is nat ral
to as5ume tfiat absorption is of a resonance nature and is realized in the 2P3/2-~P1/2
transition of atomic iodine. It is obvious that for realization of this mechanism
a large number of iodine atoms in the ground state and the presence of a process
contradicting absorption saturation are required. The accumulation of iodine atoms
in the ground state is realized by several channels, but the process of srimulited
Olnis~io~n (4) itself is the basic process in the presence of the input signal. It
must be noted that thE: transition of the medium to the absorbing state takes place
in a time appreciably less t.:sn the lifetime of an atom in the excited state T1 >
0.1 millisecond and much greater than the transverse relaxation time T2 < 10 nano-
seconds; therefore cannot convert the medium to the absorbing state.
50
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The inversion, as is easy to demonstrate on the basis of the balance equations
which are valid in the given case, asymptotically approaches zexo.
_ In parallel with process (4), a recombination process (5) develops which leads to
accur.iulation of iodine molecules. Let us note that in the postphotolysis stage
the reaction of inverse recombination of the iodine atoms with the radicals is not
considered as a result of absence of radicals which are quickly bound into complexes
in process (2~. Molecular ~odine, which is an extraordinarily eff ective quencher
of the state P1/2 leads to the occurrence of another channel for the accumulation
of iodine atoms in the ground state in process (6).
tts was demonstrated in [8], the process of thermal dissociation of the initial alkyl
iodiJe (3) can take place independently, which also leads to an increase in the
I(2P3/2) atom concentration. The rate of this process is determined by the tempera-
ture of the active medium and, according to the autbQrs o3 refereice [9], at tem-
peratures close to critical (_1000 K), it can reach 10z3 cm x sec , which must
lead to total decomposition of C F I into radicals and unexcited iodine in the
time --10 microseconds. Under the conditions of the investigated experiment, the
process of intense tliormal dissociation does not occur. First, this follows from
the fact that amplification of the pumping pulse was observed in the slave mode.
Secondly, on conversion of the amplifying stage to the lasing mode by installa-
tion of an additional resonator, a free-running pulse was recorded which lasts until
the end of the pumping current pulse, which also indicates the absence of intense
pyrolysis in the amplif ying stage for the used pumping levels. With an increase in
the pumping level, the amplifying and lasing characteristics of the stage were
reproduced in the same form; therefore it is possible to assume that in the analyzed
version the temperature of the active medium is f ar from critical. By estimates, for
T= 700 1:, the rate of the optical transitions exceeds by several orders the rate of
i he r-m;, 1 dissociation and, consequently, for investigation of driven amplif ica-
tion, it is sufficient to limit ourselves to consideration of the processes (4)-(6).
The amplifying medium can be represented in the form of a three-level system with
poFulations of the lower and upper laser states N and N and the state correspond--
ing to molecular iodine, N3. The hfs levels can le ignoied as a result of the
single-frequency spectrum of the input signal (line F= 3 to F= 4 with fast relaxa-
tion between its halflevels [10]). The system of constitutive relations has the form
X=-a/0 (1+(gz1gj))-SNeA'z I14-(K2/Bi)1-f-2f; f=1Vs=kIV~1Vo,
where A=N2-92N,!g,; Q is the amplification cross section; S is the quenching
rate constant of the excited atoms by iodine molecules; k is the rate constant of
ttie process (5); N0 is the concentration of particles M in ternary collisions.
Let us consider the variation of the inversion with time at a fixed point of the
amplifier, considering the intensity given in the form I= Ipexp (-t/'r), which with
respect to tlie upper bour_d suf f icient.ly reflects fhe shape of the pulse
recorded experimentally. If we consider that after passage of the pulse f ront the
~ variation of the concentration N3 of molecular iodine in the time interval where
ti3 1 for QA 0 L > 2.
The conclusion based on the determination of high efficiency of the process of re-
combination accumulation of molecular iodine is fully in accordance with the re-
sults of the experimental projects [7, 9] in which the formation of molecular iodine
at rates of -1040 cm 3�Sec'1 was recorded directly for the pyrolysis mechanism of
population of the state'2P3 2 with a rate close to the rate of stimulated transi-
~ t io ns in the amplificat3~n process. Thus, the deformation of a long laser pulse
in the iodine system during nonlinear driven amplification can be
expla3.ned within the framework of a model taking into account the interrelation of
the collision processes of quenching the excited state of the iodine atom and
recombination accumulation of molecular iodine.
Characteristic features of the amplification process in the investigated system per-
mit its use to shape uiicrosecond and, with additional amplification, even shorter
radiation pulses. The possibility of further shortening of the pulse is easy to
demonstrate in the example of an input pulse in the shape I= ID exp (-t/'[). Accord-
ing to [13], the level 1/e output pulse duration is
(1)
of beam cross section. For 6n-1 and 5-3-4 the value of T/TOUt Will be 20-50 and,
consequently, a pulse with a duration of -10 microseconds easily shaped in a low-
power preamplification stage, can be converted to a nsnosecond pulse during subse-
quent amplification.
where d= Q~~L, and n is the photons in the input pulse per unit area
An experiment in successive pulse amplication in a multistage system was run on the
previously used device after introducing an additional preamplif ier into the system
witn an active medium 25 cm long, identical to the laser stage with respect to the
remaining parameters. The final amplifier was a stage based on a cavity,pumping tube.
A laser with ring c:~vity and additional mirror [14] (reflection coefficient 4%)
was used to suppress self-stress of the resonator mirror amplifiers of the laser.
In experiments with filling the stages to a pressure of 15-30 mm Hg, the pulse
p~,wc~r at the output was 1-3 joules. It is possible to determine the peak emission
power by the burnup of a graphite calorimeter surface observed experimentally (under
defined conditions and without preamplif ier) under the effect of an unfocused beam.
The power density reyuired to form a flame on the graphite surface is -5 Mwatts/
cm2 [15]. llence it can be concluded that for a total beam power of -20 Mwatts/
cm2 (S = 5 cm2), the pulse obtained in the investigated system will have a length
of -100 nanoseconds. This conclusion agrees with the results of direct measurements
of the pulse duration on a tiigh-speed oscillograph: a halfheight pulse duration of
50-100 nanoseconds was recorded in individual experiments.
itius, from the presented results it follows that the method of nonlinear amplifica-
tion of free--running iodine laser pulses pernaits powerful emission pulses witfi
53
Key: 1, output
total number001"f*
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sufficient intensity, for exatDple, fox anlplicati,on izl a nonlinear optical system and for
the study of the interaction of radiation w-itli matter, to be obtained simply and
without additional modulators.
It is possible to formulate the basic results as follows:
1. An experimental study was made of the transmission of a free-running photodisso-
ciation laser emission pulse through a resonantly amplifying medium with synchronous
or lead pumping of the amplifying stages. A sharp reduction in length of the pulse
was demonstrated on transition to driven amplification. 2. It was shown that for driven amplification the laser pulse is chopped by non-
pyrolysis transition of the medium to the absorbing state. This is connected with
the presence of quenrhing collisions with 1 2 molecules formed during recombina-
tion of atoms in the ground state. In this mode, even in the presence of pulse
front amplification, the emission power at the amplif ier output can be less than
the input pulse powei-.
3. It is demonstrated that by optimizing the synchronization of the stages it is
possible to shape emission pulses with intensity exceeding 1 Mwatt/cm2 from low-
power pulses emitted by a free-running photodissociation laser.
BIBLIOGRAPHY
l. E. Fill, K. Hohla, G. T. Schappert, R. Volk, APPL. PHYS. LETTS., No 29, 1976, p
805.
2. P. G. Kryukov, V. S. Letokhov, UFN (Progress in the Physical Scie.nces), No 99,
1969, p 1969.
3. I. M. Belousova, B.D. Bobrov, V. M. Kiselev, V. N. Kurzenkov, KVANTOVAYA ELEKTRO-
NII:A (Quantum Electronics), No 1, 1974, p 1389.
4. B. V. Alekhin, B. V. Lazhintsev, V. A. Nor-Arevyan, N. N. Petrov, B. V, Sukhakov,
KVANTOVAYA ELEKTRONIKA, No 3, 1976, p 2369.
5. L. Ye. Golubev, V. S. Zuyev, V. A. Katulin, V. Yu. Nosach, 0. Yu. Nosach, KVANTO-
VAYA ELLKTRONIKA, No 6(18), 1973, p 23.
6. L. I. Zykov, G. A. Kirillov, S. B. Kormer, S. M. Kulikov, V. A. Komarevskiy, S. A.
Sukiiarev, KVANTOVAYA ELEKTRONIKA, No 2, 1975, p 123.
7. U. B. Danilov, V. G. Korolenko, I. L. Yachnev, PIS'MA V ZHTF (Letters to the JoLr-
nal of Technical Physics), No 3, 1977, p 207.
8. V. Yu. Zalesskiy, ZHLTF (Journal of Experimental and Theoretical Physics), No 62,
1971, p 892.
9. I. M. Belousova, 0. B. Danilov, N. S. Kladovikova, I. L. Yachnev, PIS'MA V ZHTF,
No 40, 1970, p 1562.
10. Ye. A. Yukov, KVANTOVAYA ELEKTRONIKA, No 2(14)~ 1973, p 53.
54
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11. L. S. Ycrshov,V. Yu. Zalesskiy,, A. M. Kokushk.in, KHIMIYA VYSOKIKH ENERGIY
(Iligh-Energy Chemistry), Plo 8, 1974, p 225,
12. C. C. Davis, R. J. Pirkle, R. A. Mcfarlane, G. J. Wolga, IEEE J., QE-12, 19769
p 334.
13. L. Frantz, J. Nodvik, J. APPL. PHYS., No 34, 1963, p 2346.
14. V. N. Kurzenkov, KVANTOVAYA ELEKTRONIKA, No 6, 1979, p 1705.
15. A. I. Barchukov, F. V. Bunkin, V. I. Konov, N. N. Kononov, G. P. Kuz'min, G. A.
Mesyats, N. T. Chapliyev, KVANTOVAYA ELEKTRONIKA, No 3, 1976, p 1534.
COPYRIGHT: Izdatel'stvo "Radio i svyaz "Kvantovaya elektronika", 1981
10,845
CSO: 1862/220
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UDC 662.613+535.339+533.601
CHARACTERISTICS OF EXPLOSION GAS DYNAMIC LASER UTILIZING ACETYLENE
COMBUSTION PRODUCTS
_ Moscow KVANTOVAYA ELEKTRONIKA in Russian Vol 8, No 5(107), May 81
(manuscript received 15 Aug 80) pp 1002-1011
[Article by A. B. Britan, V. A. Levin, S. A. Losev, G. D. Smekhov, A. M. Starik and
A. N. Khmelevskiy, Mechanics Institute of Moscow State University imeni M. V.
Lomono5ov]
[Text] Abstract: A study is made of the gain and specific
stored energy of acetylene combuatiaa-products after the
multi-nozzle grid of an explosion gas--dynamic laser
(GDL). Nitrous oxide is used together with oxygen
of the air as the oxidizing agent. The calculated
gain is complared with the experimental data. An
analysis is made of the gain and specif ic stored
energy as functions of the composition of the mix-
ture and flow stagnation parameters.
At this time, the creation of a highly efficient GDL and optimization of it with
respect to all defining parameters are an urgent protalem of laser engineering. An
important characteristic of a laser system is the gain K, which is related to the
population of the laser levels, the inversion and, in the final analysis, deiines
the emission power generated by the laser. The results of comparing experimental
values of K with the calculated values permit determination of the possibilities
and reliabiYity of the calculation procedures [1]. In these studies the experiments
in which the laser mixture is formed directly as a result of burning var.ious fuels
are of the greatest interest. Measurements performed on a laboratory setup have
made it possible to obtain information under conditions approaching the conditions
in a real GDL to the maximum, but the applicability of the results and the range of
- parameters obtained in this way are limited by the choice of a specific type of fuel
[2-4].
llevices in which an additional energy source shock waves [5, 6] or pulse dis-
c:iarge in a closed volume [7] is used, have broader possibilities. The composi-
tion and parameters of the working mixture in such experiments vary within broad
limits, and this allows simulation of the flow conditions of the combustion products
of a large class of laser fuels [1]. When analyzing GDL characteristics and also
in experiments connected with more precise definition and checking of the calcula-
tion procedures, it appears expedient to combine several experimental setups of
different types within thc framework of one atudy. Gradual complication of the
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gas ccmposition f rcxn t hc simplesc standard mixes investi.gated in a shock tube to com-
plex multicomponent combustion products of real fuels allows signifi.cant expansion
of the range of investigation and discovery of the effect of individual components
on the characteristics of the GDL working raedia [8]. If a theoretical analysis is
performed on the easis of a united calculation procedure and with a fixed set of
constants, comparison of the calculation results with the experimental results per-
mits sufficiently reliable checking of the validity of the mathematical model of
the flow.
This paper is a continuation of previous shock tube studies [5, 89 9], and it pre-
sents aci analysis of inverse and energy characteristics of GDL utilizing acetylene-
air fuel combustion products where nitrous oxide was investigated along with air
oxygen as the oxidizing agent.
A GDL with cnulti-nozzle grid designed for limiting parameters p0 = 200 atm, T0 _
3000 K was used for the experiments. A general view of the gas dynamic module of
ttie unit is depicted in Figure 1 in the plane of symmetry of the multinozzle grid.
An explosion chamber 1 with blast cartridge 2 and connection 3 for connecting the
vacuum line 4 is located on the upper end of the module. Gas escapes through the
multi-nozzle grid 5 into a vacuum tank 6. The explosion chamber and nozzle grid
are mounted on the upper flange of the unit 7. The explosion chamber and vacuum
tank volumes are separated by a diaphragm B. All of the connections between the
subassemblies and parts of the device are sealed and permit evacuation of the sys-
tem to less than 20 um Hq. The explosion and pre-nozzle chamber volumes are in
practice the same (_2 liters), and the vacuum tank 6 has a volume of 200 liters.
The flow areas of the diaphragm sl and the holes in the upper flange 7 s2 are of
the same order (sl/s2 = 1.6), and they significantly exceed the flow area of the
multinozzle grid (s21s* = 720).
The nozzle length and its supersonic section were calculated unidimensionally [10]
from ttie condition of maximum generated emission power for given mixture composi-
tion and stagnation parameters. The critir_al cross sectional height h* = 0.35 mm
was selected on the basis of calculating a two-dimensianal flow, the parameters of
which corresponded to optimal [11]. The nozzle expansion ratio E a 140.
A standard system (see Figure 1) with the LG-22 continuous electric discharge C02-
laser 9 equipped with a� interrupter 10 was used to measure the gain. A capaci-
tive filter i.n the electric circuit of the laser power pack made it possible to
lower the level of emission intensity fluctuations of the laser to less than 3%.
The amplified c'miS5ion was fed through an IR f ilter 11 to a"Svod" type photoresis-
tance 12.
Uetonation of the mixture in the explosion chamber was initiated by deton.ating a
constantan wire with a resistance of about 100 ohms. Measuring the pressure in
the explosion chamber also permitted monitoring of the diaphragm rupture time and
satisfaction of the condition of constancy of the volume during combustion of the
mixture. This condition is necessary for reliable determination of the explosion
product composition and parameters.
The experimental values of the pressure in the explosion chamber and before the
entrance to the multi-nozzle grid measured at di�ferent initial pressures of the
mix Pinit are presented in Figure 2. The stagnating pressures obtained from the
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thermodynamic calculation (the solid line$) 112J lie above the experi,mental points.
Let us also note that the calculation overestimates the temperatures in the
explosion products. This is indicated by a comparison of the calculated values of
Tp (see the table) with the results of the temperature measurements performed in
[4]. Simple estimates permit explanation of this difference by incompleteness of
combustion of the acetylene [13]. According to j4], for a mix containing 4% C2H2,
T0 = 1850 K,and for a mix containing 6.54% C2H2, To = 1500 K. From the calcu-
lation it follows that combustion of the indicated mixes leads to insignif icant
variation ( 3000 K) reached in these reactions
niake it possible to obtain a medium with significant energy reserve in the vibratio-
nal debrees of f.reedom of the molecules of the mixture and to raise the specific
characteristics of the lasers.
Tn order to determine the possibility of raising the specific parameters of a com-
bustion GUL, in this paper studies were made of the inverse characteristics of the
medium obtai.ned on combustion of acetylene in an atmosphere of N20 and N2 (6.57%
C2Ii2 with 33,3% N20 and 60i' N2), in the pressure range po = 5-100 atm. The combus-
tion products of the given mix (see the table) contain almost half as much C02
as the combustion products of the mixture of 6.57% C 2 H 2 with aiT, and twice as murh molecular
fiydrogen and C0. A calculation study of the funeCion ICv = f(po) demonstrated that
in spite of high stabnation temperatures (T0 z 3100 K) in such a mix significant
bains are reachecl (1:. 0.5 m 1) in a broad range of variation of the stagnation
pressure (p0 = 25-80 atm). It is interesting that by comparison with the combus-
ti.on products ut acer_ylene-air mixes, the deactivation of the vibrations of the
N2 niolecules and the asymmetric mode of C02 takes place appreciably less sharply
ttian in the given czse. This is caused first of all by the smaller proportions of
COZ aiicl HZO and larger proportion of NZ in the mix and, secondly, a decrease in the
total iumber of particles per unit volume with a.: iiicrease in T0.
These factors predominate over the increase in the relaxation process rate as a re-
sult of the increased temperature. Comparison of the theor.etical results and the
measured values of the gain (Figure 4) demonstrated that the calculation procedure
gives a correct representation of the kinetics of the physical processes in the
given molecular system. The calculation results agree well with the experimental
data of p0 = 25 atm. Divergc:nce of the experimental and calculated values of Rv
54
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ac % 30 aLm obviously i,s explained by ttie following causes. When using nitrous
uxicie as the oxidizing agent, the processes of i.gni,ti,on and combustion of the work-
ing mixture take place more rapidly than combustion of mixes based on air. As a
rasult, the pressure in the explosion chamber builds up quickly, which complicates
the selection of the corresponding diaphragms. In the majority of experiments for
pinit ' S atm the diaphragms ruptured appreciably before the maximum pressure was
reach^_d in the combustion products. This, in turn, led to indeterminacy in the
value of Pfinal and in the combustion product composition. The possible presence of
unreacted N20 in the mixture can significantly increase the deactivation rate of the
upper laser level of the CO2 molecule (OQ0l), inasmuch as the 0001 state of the N20
molecule is energywise simiIar to the 00~1 state of CO2 and (v = 1) Nz (energy
def ects DE = 178 and 152 K, respe tively). The W`-process rates bet~reen these
states are quite large (--10-13 cm~/sec), and the relaxation processes in the N20
itself take place it nn appreci.ably higher rate than in C02 [17, 231.
-r
,K~,.H
i o0
�
o
; o o ~o
~ o� o ~ �o o
0
I
~
9 20 40 60 D,7, Q171M ( c" )
Figure 4. Gain as a function of stagnation
entrance to the multi-nozzle grid; mixture
:120 and 60% N2; measurements near the
grid; dotted Iine calculation results.
hey: a. atm
pressure before the
of 6.67% C2HZ with 33.33%
tip of the multi-nozzle
A detailed study of GDL based on acetylene combustion in an N 0 atmoaphere requires
more careful development of tlie experimental procedure and meihods of calculating
tfie combustion products of the indicated mixes.
r'or comparison of varLous fuels by efficiency it is necessary to consider the condi-
tions which permit extraction of the energy stored in the C02 and N2 molecular vi-
brations at the exit from the multi-nozzle grid. In the general case the problem
Cl)l1S1SCS in converting the maximum proportion of this energy to optical radiation
before collision deactivation leads to numping of this energy into translational
ancl rotational degrees of freedom of the mixture molecules. Without giving specific
examples of a resonator, the specific emission power stored per unit mass of the
gas in the inverse transition can be determined by the expression [1, 10]
n R
Ey r f r r I
'n - Fl emn I ~'3bCOe'. FObN, - l13 bGO, 14 bN~]Kv~01r (2)
wtiere ~Fj=rjujl(1-yi); j=3, 4; rj is the multiplicity of degeneration of the jth mode;
Omn is the radiation f requency, K; the term [93 ko, '1' 14 bN,1Kv-o characterizes the
mean number of quanra in the asymmetric C02 vibrations and the N2 vibrations for zero
65
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Em(a)
\ .s I
~ I \
10 r
( I \
D 20 40 60 00. amn (b)
Figure 5. Specific stored energy as a function of stagnation pressure:
1-- mixture of 4% C 2 H 2 and air, T0 = 1850 K; 2--- mixture of 6.54% CzH2
and air, T= 2500 1C; 3-- mixture of 6.67% C2H2, 33.33% N20 and 60%
N2, To = 3QU0 K; calculation [25]; calculation [2].
Key: a. joules/gram b. atmospheres
~;ain of the medium. The expression for ~'3 ~ y; i(i -y3~ is easily obtained by equati.ng
the expression for the gain to zero [1, 10]. As a result, we have
ys = yseXP { ~Boo., l (j- I) - Bo-o 1(1 + 1)1/T} B, o�o lBwl� (3)
For calculation of ~4=Y41 0 -y4) , we assuL_ that y3 = y4 exp (-E3/4/T).
'The results of the calculations of En for the three investigated mixtuxes are pre-
sented in Figlire 5. It is obvious tWat for each of the investigated mixes the value
of E� decreases with an increase in the stagnation pressure. This is explained by
an increase in the relaxation rate of the energy stored in the vibrations of the gas
molecules with an increase in p0. The maximum values of the stored specific emis-
ion powe r are reached for low pressures of the active medium (p0 = 6-10 atm), and
for mixtures of 4% C H with air and 6% C H with air the maximum values are 35 and
70 joules/g, respectively, and for mixtures2based on acetylene and nitrous oxide,
even 125 joules/g, which is not less than the value of En for mixing lasers [23].
Inasmuch as the efficiency of the resonators with optimal mparameters (transparency
ana flow length) can be quite high (n = 0,7 to 0,75) when using the indicated mix-
tures it is possible to obtain recordPhigh values of the speci.fic emission power.
Witli respect to efficiency of acetylene-air fuels it is necessary to note that for
small (-4%) acetylene contents the efficiency of such fuels is quite close to the
efficiency of a benzene-air mixture. The calculated values of Em obtained in [2,
25] for a benzene-air mix are shown in Figure 5 by the dots. The stagnation
parameters and mixture compositions for the selected conditions compare.
Thus, the obtained results indicate the prospectiveness of using acetylene as
a fuel iTi combustion CUL. Obviously the most prospective is use of three-component
_ mixtures oE C2H2-N2O-N2, the combustion of which makes it possible to obtain an
active medium with tiigh specific emission powei- (E~ - 120 joules/g) for gains of
I~ z 0. 4-- 0. 5 m 1.
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In conclusion, the authors express their appx'eciati.on to M. S, Dzhidzhoyev far use-
ful discussions of the results of the ,.aper, V. V. Lugovskiy for assistance in
performing the experiments, and V. N. Mekarov and Yu. V. Tunik for performing cal-
culations when designing the nozzles.
BIBLIOGRAPIiY
l. S. A. Losev, GASODINAMIC H ESKIYE LAZERY (Gas Dynami,c Lasers), Moscow, Nauka, 1977.
2. M. G. Ktalkherman, V. M. Mal`kov, ISSLEDOVANIYE RABOCHEGO PROTSESSA GAZODINAMI-
CHESKII:H LAZEROV (Study of the Working Process of Gas Dynamic Lasers), Edited by
V. K. Bayev, Novosibirsk, ITPM, 1979.
3. N. V. Yevtyukhin, A. P. Genich, G. B. Manelis, FIZIKA GORENIYA I VZRYVA (Combus-
tion and Explosion Physics), No 4, 1978, p 36.
4. V. V. Ivanov, "Candidates Dissertation," In-t prcblem mekhaniki AN SSSR, Moscow,
1978.
5. A. B. Britan, A. M. Starik, ZH. PRIKL. MEKH. I MEKHN. FIZ.,(.Tournal of Applied
Mechanics and Technical Physics), No 4, 1980, p 27.
6. A. Yu. Volkov, A. I. f)emin, et al., TRUDY FIAN (Works of the Physics Institute
of the USSR Academy of Sciences), No 113, 1979, p 150..
7. A. I. Odintsov, A. I. Fedoseyev, D. G. Bakanov, PISIMA V ZHTF (Letters to the
Journal of Technical Physics), No 2, 1.976.
8. A. B. Britan, S. A. Losev, 0. P. Shatalov, KVANTOVAYA ELEKTRONIKA (Quantum
Electronics), No 1, 1974, p 2620.
9. A. B. Britan, R. I. Serikov, A. M. Starik, V. M. Khaylov, IZV. AN SSSR, SER.
iYiEK:WiII:A ZHI DKOSTEY I GAZOV (News of the USSR Academy of 5.:iences. Fluid and
Gas Mechanics Series), No 1, 1980, p 203.
10. S. A. Losev, V. N. Makarov, KVANTOVAYA ELEKTRONIKA, No 3, 1976, p 960,
11. V. N. Makarov, Yu. V. Tunik, Zli. PRIKL. MEKH. I MEKHN. FIZ., No 5, 1978, p 23.
12. G. D. Smekhov, V. A. Fotiyev, ZH. VYCH. MATEM. N MAT. FIZ. (Journal of Computer
riathematics and Mathematical Physics), No 18, 1978, p 1284.
13. A. I. L1'natanov, I. I. Srizhevskiy, ZH. FIZ. KHIMII (Physical Chemistry Journal),
No 152, 1968, p 1294.
14. A. P. Genich, N. V. Yevtyukhin, S. V. Kulikov, et al., ZH. PRIKL. MEKH. I MEKHN.
FIZ., No 1, 1979, p 34,
15. A. S. Eiryukov, TRUDY FIAN, No 83, 1975, p 13.
16. V. V. Yegorov, V. N. komarov, TRUDY TSAGI IM. N. YE. ZHIJKOVSKOGO (Works of the
Central Institute of Aerodynamics imeni N. Ye, Zhulcovskiy), No 1959, 1975, p 35.
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17. Yu. A. Kulagin, 'rRUllY FIAN, No 107, 1479t p lla,
18. G. I. Kozlov, V. N. Ivanov, I. K. Selezneva, FLZTKA GORENIYA I VZRYVA (Combusr{on
and Explositon Physics), Vol 15, 210 4, 1979, p 88.
19. V. A. Levin, A. M. Starik, IZV. AN SSSR. SER. MEKHEINIKA ZHIDKOS'rEY I GAZOV, No 2,
1980, p 102.
20. J. A. Blauer, G. R. Nickerson, AIAA Paper, 74-536, 1974.
21. V. A. Levin, A. M. Starik, NERAVNOVESNYYE TECHENIYA GAZA S FZZIKO KHIMICHESKIMI
PREVRASHCHENIYAMI (Nonequilibrium Gas Currents with Physical-Chemical Conver-
sions), ;Ioscow, Izd-vo MGU, 1980, p 25.
22. R. L. Center, J. C:IIGM.PHYS., No 59, 1973, p 3523.
23. A. E. Cassady, A. L. Pindro, J. F. Newton, RAKETNAYA'fEKHIKA I KOSMONAVTIKA
(ltocket Engineering and Astronautics), Vol 17, No 8, 1979, p 59.
24. J. Anderson, GAZOllINAMICHEShIYE LAZERY. WEDENIYE (Gas Dynamic Lasers. Introduc-
tion), Moscow, Mir, 1_979.
25. R. J. Hill, N. T. Jewell, A. T. Jones, RAKETNAYA TEKHNIKA I KOSMONAVTIKA, Vol 16,
No 3, 1978, p 119.
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UDC 537.521.7
ATMOSPtiLRIC AIR BREEIKDOWN BY NEODYMIUM LASER EMISSION FOR LARGE FOCAL POINT DIAMETERS
Moscow KVANTOVAYA ELEKTRONIKA in Russian Vol 8, No 5(107), May 81
(manuscript received 4 Oct 80) pp 1122-1123
[Article by Ye. V. Gfiuzliukalo, A. N. Kolomiyskiy, A. F. Nastoyashchiy and
L. N. Plyashkevich]
[Text] Abstract: A studywas made of the threshDld power density
wTT for large focal point diameters. A decrease in wIT
from 70 to 2 GW/cm2 was detected with an increase
in d from 0.2 to 2.0 mm, which contradicts the
avalanche breakdown theory, according to which
for d> 100 microns w should be independent of
d. Estimates are presented which indicate that
the reduction in w can be explained by the
effect of ion-molecular reactions.
l. Optical breakdown of air was investigated earlier in [1-5]. In the experiments
of [1], a study was made of the threshold density w of the emission power of a
neo.iymium laser as a function of the diffusion lengh ll at an air pressure of p=
8.15 atm. It was found that in the interual of A= 15 to 70 microns the threshold
varies approximately according to the law w- ti A-312, in spite of the fact that for
n� nbreakdown z 5 microns the diffusion losses of the electrons are insignif icant
and wIT the~--etically [6] should not depend on A.
Efforts to explain this divergence with theory, for example, using the hypothesis
of "diffusion-similar" losses [1] were unsuccessful [6]. Nevertheless, there was
hope that for still larger values of /l, in accordance with theory, the curve for wTr
as a function of A would reach saturation. In order to check this proposition,
measurements of w for large focal point dimensions were needed. The power of the
lasers used in experiments [1-5] for this purpose was insuff icient.
We performed studies of w on a powerful laser [7], which under unimodal conditions
generated laser pulses T~ 200 nanoseconds long (Figure 1). The radiation was
focused in the air by lense5 with focal lengths of f= 1.4 and 14.0 meters.
The focal point diameters were d= 0.2 and 2.0 mm, respectively. Breakdown was
observed for a pulse power E> 4.5 to 5joules in the first case and E> 12 to 15
joules in the second case; the thresholds were 70 and 2GW/cm2, respectively. A
- photograph of the laser spark near the threshold is shown in Figure 2, a. When the
tllreshold was exceeded w� wn , a long laser spark occurred consisting of individual
69
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glowing centers (Figure 2, h), which resembled the spark observed by other authors
(see the ref erences in [8]).
Thus, a further reduction in w is detected with an increase in the size of the
focal point to d= 2.0 mm. The law of variation of w 7T is approximately the same as
in [1]. The electron losses as a result of diffusionwere insignificant in our
experiments (with a"margin" of two or three orders); therefore it is natural to
assume that for large focal point dimensions the breakdown mechaniam is different
than is proposed i.n avalanche theory.
Let us discuss the effect of ion-molecular reactions as one possible cause of di-
vergence with theory [9]. The following reactions can take place in the air [10]
N, -L N: Na T e, N~ 02 N202 + e, and so on. (1)
The lifetime of the excited molecules depends on the optical thickness of ehe gas (for
example, in the case of Lorentian or doppler contour of the line, the lifetime of a
resonance photon Teff1' d[11]); therefare an increase in size of the focal point
should lead to a decrease in wTF.
Let us present some estimates. Neglecting electron diffusion, the ion multi-
plication rate [9]
(2)
r~(V:Vr), / s_~~=T~
Key: a. eff
where ve is the molecule excitation frequency by electron impact; vi is the ioniza-
tion rate according to (1). (Let us note that in the expression for Vi it is pos-
sible also to consider a correction for ionization of N2 by laser emission; for
C02-lasers [5] this ionization does not occur, but the eff ect of a reduction in wTr
with size of the focal point is retained.)
Setting the reaction cross section (1) 6i - 10-16 cm2 [10], we hav* vi - 10$ sec-1
and, consequently, for breakdown it is sufficient to insure that v- 109 sec, for
which, in general, smaller w are required than in the case of direct ionization by
electron impact. (UnfortunaLly, the performance of detailed calculations is com-
plicated as a result of absence of reliable experimental cross sections). It is
appropriate to note tliat the effect of ion-molecular reactions can explain deviations
from Townsend's law at increased gas pressures [10] and high ionization in the glow
discharge in molecular nitrogen [12].
In [13], the reduction of w for large d was explained by the presence of aerosol
particles in the gas; unfortunately, this paper contains obvious errors (for example,
the proposition of the supposed reduction in inelastic losses with excitation of
resonance levels; see the criticism in 16]). Solid particlessuspended in the air
can produce a diffusion-like effect for long pulses T- 1 millisecond and relatively
high particle concentration [9]. For short laser pulses it is ununderstandable how
breakdown occurring, for exa:nple, near an aerosol particle, can encompass the entire
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laser beam cross section, for the known mecha.nism& of propagation of the front (slow
combustion, light detonation 16J) do not provide the required speed.
a
50cM G 50cM
Figure 1. Snape of a laser pulse with Figure 2. Photograph of a laser spark
~ time (sine period 20 nanoseconds). in the air (f = 14.0 m) near breakdown
threshold (a) and on noticeably Pxceeding
the threshold w/w7, z 3 (b).
The estimates made indicate that ion-molecular reactions can play an important role
in optical breakdown of atmospheric air. At the same time, air breakdown under
actual conditions, as follows from the accumulated facts, can have a highly comples
nai L1rC, and it is impossible a priori to exclude the effect of other factors, in-
cluding, for example, the presence of atmospheric aerosols.
The authors express their appreciation to N. G. Koval'skiy for his discussion.
BIBLIOGRAPHY
1. A. llot, R. N. Yerand, D. Smith, DEYSTVIYE LAZERNOGO IZLUCHENIYA (Effect of Laser
Emission), Moscow, Mir, 1968, p 42.
2. R. Tomlison, Ye. Damon, G. Busher; DEYSTVIYE LAZERNOGO IZLUCHENIYA (Effect of
Laser Emission), Moscow, Mir, 1968, p 52.
3. S. Lencioni, APPL. PHYS. I.ETTS., 23, 12 (1973).
4. M. P. Vanyukov, et al., PLS'TA V ZhETF (Letters to the Journal of Experimental
and Tiieoretical Physics), Vol 3, 1966, p 316.
5. f). C. Smitti, APP1.. PNYS. LETTS., Vol 19, 1971, p 405.
6. Yu. P. Rayzer, i.A'/.ERNAYA ISKRA (Laser Spark), Moscow, Nauka, 1974.
7. V. V. Alexandrov, et al., NUCLEAR FUSION. SUPPL., Vol 15, 1975, p 113.
8. V. A. Parfenov et al., P1.S'TA V ZhETF, Vol 2, 1976, p 731.
9. A. F. Nastoyashchiy, KI:ANTOVAYA ELEKTRONIKA (Quantum Electronics), Vol 7, 1980, p 170.
10. E. U. I.ozanskiy, 0. B. Firsov, TEORIYA ISKRY (Spark Theory), Moscow, Nauka, 1975.
71
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11. B. M. Smirnov, FIZIKA SLABOIONIZOVANNOGO GAZA (Physics of a Weakly Ionized Gas),
Moscow, Nauka, 1978.
12. L. S. Smirnov, D. I. Slovetskiy, I. A. Sergeyev, TEPLOFIZ, VYS. TEMPER. (High-
Temperature Thermophysics), No 15, 1977, p 15.
- 13. D. S. Smith, J. APPL. PHYS., No 48, 1977, p 2217.
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Itd ME140RY OF EDUARD SERGEYEVICH VORONIN
Moscow I:VANTOVAYA ELEKTRONIKA in Rusaian Vol 8, No 5(107), May 81 p 1152
[Article by S. A. Akhmanov, N. G. Basov, F. V. Bunkin, V. S. Zuyev, Yu. A. I1'inskiy,
I. N. Matveyev, V. V. Migulin, A. L. Mikaelyan, A. M. Prokhorov, V. S. Solomatin,
M. F. Stel'makh, A. P. Sukhorukov and V. S. Fursov]
[Text]
Soviet science suffered a severe loss on 12 March 1981, when a great scientist in the
field of quantum electronics and nonlinear optics, doctor of physical and mathemati-
cal sciences, USSR State Prize Laureate Eduard Sergeyevich Voronin died at the age
of 53.
L. S. Voronin devoted more ttan 30 years of his life to science, in particular,
radio physics and nonlinear optica. He pexformed a number of important studies in
the fiE:ld of the physics of nonlinear oscillationa, including pulse synchronization
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of autooscillators. Iie ohtained tfie brightest xesults in the field of coherent and
nonlinear optics when studying the processes of the conversion of infrared radiation
to the visible band using parametric interactions of light waves. Recently Eduard
Sergeyevich conducted intense studies in the field of nonlinear adaptive optics.
E. S. Voronin was awarded the USSR State Prize in 1975 for his work in applied op-
tics.
E. S. Voronin was an active member of the Board of Editors of the KVANTOVAYA ELEK-
TRONIKA (Quantum Electronics) Journal; he was on a number of scientific problem
- and coordination councils, and he participated in the organization of all-union
conferences on quantum electronics and laser physics.
All of the scientific life of E. S. Voronin was continuously connected with Moscow
State University. tie was for a long time a co-worker with R. V. Khokhlov in the
physics department of Moscow State University. A talented scientist and teacher,
Eduard Sergeyevich educated many students.
E. S. Voronon, a member of the Communist Party, combined his scientific and pedago-
gical activity with a large amount of responsible social work.
Eduard Sergeyevich always distinguished himself by exceptional cheerfulness, warmth
and responsiveness in his relations to people.
The bright memory of Lduard Sergeyevich Voronin will remain in our hearts forever.
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UDC 621.378.33
CLOSCD-CYCLE FAST-FLOW PULSL'D C02 LASER WITH CARBUN DIOXIDE RECOVERY UNIT
Moscow KVANTOVAYA ELEKTRONIKA in Russian Vol 8, No 5(107), May 81
(manuscript received 24 Oct 80) pp 1134-1136
[Article by A. V. Artamonuv, A. G. Borkin, A. P. Dzisyak, S. V. Drobyazko,
A. 1. Lazurclienkov, A. A. Nekrasov and Yu. M. Senatorov]
[Text] Abstract: The possibility of stabili.zing the radia-
tion power and mixture compositi.on in a repetitively
pulsed C02-laser by palladium-catalytic regene-
ration of carbon dioxide is demonstrated. The
small-signal gain was measured in working mix-
tures of various compositions, and it was demon-
strated that the decrease in gain with dissocia-
tion of C02 is connected both with a decrease in
the C02 concentration and with an increase in
the CO and 02 concentrations.
1. In closed-cycle C02-lasers, the decrease in radiation power is primarily connec-
ted with dissociation of the carbon dioxtde [1-5]. In order to prevent a decrease
in power, the working medium of a CO-1.aser must be regenerated. One of the methods
of stabilizing the chemical composttion of the working mixture of the laser and,
consequently, the output power of the emission is heterogeneous-catalytic oxidation
of carbon monoxide [1, 6].
In this paper a study is made of the possibility of atabilizing the emission pulse
power by palladium-catalytic regeneration of carbon dioxide, and the weak-signal
gain is measured in laser mixtures of various compositions.
2. The experiments were run on a repetitively pulsed fast-Flow laboratory C02-laser
with transverse pumping of the gas [7]. The total volume of the gas channel was 1.5
m3, the electrode gap volume was 0.8 liters. The gas was pumped by a 2DVN-1500
pump. All of the experiments were run on a mixture of C02: N 2 : He = 10 : 45 : 45
with a total pressure of 80 nun Hg. The energy inpur to the discharge gap was
175 joules/liter-atmospiiere, and the pulse repetition frequency was 200 hertz. The
teaipeiature of the gas and the catalyst was measured by chromel-copel thermocouples.
Ttie bas flow rate ttirough the reactor was determined using a Picot-Prandtl tube with
MCM-250-0.02 differential micromanometer. The gas mixture composition was analyzed
on the LKh"1-8NID chromatograph. The pulse radiation power was measured by the TPI-1
graphite calorimeter in the monopulse mode. The gain was measured by the transmis-
sion methoci by a stable C02-laser using the procedure outlined in 181. Palladium
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black on a stainless steel carrier made in the form of grids with wire diameter of
0.25 mm and mesh size of 0,5 mm2 was used as the catalyst. The palladium content
was 0.3% by weight. 't'he total weight of the catalyst was 0.5 kg, and the service
liLe, more than 100 hours.
_ o~
V
J:Vn
Figure 1. Variation of the grid temperature
with respect to reactor length for various heat-
inb element voltages (n grid number).
Key: a. heuting element b. volts
5
~ Q
=.�~.Aw (A)
' ---r---------~-------
.
t
� ~
� � -
i
~ P' - �
7 w B 12 16 :2 i, nuN (B)
6
Figure 2. ilegree of dissociation oc (a) and pulse
power epulse (b) as a function of time
wi thout Cc)2 recovery (1) and with recovery at
v,~r I uu:; cnCalyat temperatures; T- 250 (2), 330
(3) ancl 400� C (4).
Key: A. c pulse' joules
B. t, minutes
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1431
7 3 5 7 9~ 11 13 15 n
,
cr, �o
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~y.~ Ky'"axlA:ro.a=i~KypiAco.l
(a) b
~
i
~
L
,0
0
S
3
29 pl~, Mn pm cm.
10 pC0,%, Mn pm. cm. (b)
Figure 3. Gain at the peak as a function of C02
pressure (1) and CO (2) and 02 (3) additive pres-
sure at W= 105 joules/(liter-atmosphere), p=
150 mm lig, N2:He = 1:1.
I:ey: a. relative units
b. mm Hg
3. The catalytic reactor was a metal box w i t h 5 kW a d j u s t a b 1 e-p owe i�
coi 1 heac ing clement ac the ent ranre. The reactor was installed in the gas
loop channel (after the discnarge chamber) and covered part of its cross section.
The grids with palladium black were installed across the flaw with a spacing of 2 mm
between them. The pressure drop on the cold catalytic reactor did not exceed -10
mm H20 for a gas velocity in the free channel of -20 m/sec. The temperature varia-
tion of the catalyst grids with respect to reactor length (along the flow) is given
i n F igu re 1. The tempc rac u re gradient is explained by radiant heating of the
first grids. It was discovered that the given catalyst is unstable at temperatures
ahove 500� C. This is probably connected with a sharp decrease in adhesion of the
palladium black to the metal substrate.
4. Fibure 2 shows the degree of dissociation of the C02 (a) and the pulse emission
power as functions of time for a mixture of C02:N2:He = 10:45:45. The curves 1
show the variation in the degree of dissociation and pulse power without carbon
dioxide recovery. For a value of az 10%, the decrease in the pulse emission power
is -27%. With palladium-catalytic recovery of the C02, the degree of dissociation
decreases as its temperature rises (curves 2-4).
Witt a decrease in the degree of dissociation, the pulse power increases (curves 2-
4) ad for a= 1% it differs by -3% from the initial power. Inasmuch as the emis-
'.ion power increases linearly as a function of the C02 content in the mixture only
for a proportion of C02 < 15%, the results and the conclusions presented in this
paper pertain to ternary mixtures with low C02 content [4].
When eyuilibrium is reached, the carbon monoxide formed as a result of C02 dissocia-
tion must be "burned" in the catalyst, that is,
Qto=aP (no-f-an)-
-r
where cx0 is the degree of dissociation of the C02 in a single pass of the gas
ttirougli ttie discharge chamber; a is the equilihrium degtee of dissociation of CO2 ;
Li is the degree of conversion ofncarbon monoxide in the catalytic reactor; a is the
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proportion of the flow of gas through the catalytic reactor (considering the tem-
perature in the reactor [91).
As a rule, a � a, and it is possible to make the value of S equal to one, in-
creasing thenamoun2of catalyst and its temperature; therefore from (1)
an=aoia.
(2)
Inasmuch as a0 = klnet, where kl is the C02 dissoci.ation rate constant for electron
impact; ne is the electron concentration; T is the time the gases are in the dis-
charge zone in a ti