SOVIET ATOMIC ENERGY VOL. 32, NO. 1

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Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Russian Original Vol. 32, No. 1, January, 1972 Translation published July, 1972 SOVIET ATOMIC ENERGY ATOMHAFI 3HEPINFI ? (ATOMNAYA ENERGIYA) TRANSLATED FROM RUSSIAN lc- CONSULTANTS BUREAU, NEW YORK Declassified and Approved For Release 2013/0'3/01 : CIA-RDP10-02196R000300100001-0 ; Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 SOVIET ATOMIC ENERGY , Soviet Atomic Energy is 'a cover-to-cover translation of Atomnaya Energiya, a publication of the Academi of Sciences sof the USSR. An arrangement with Mezhdunarodnaya Kniga, the Soviet book export agency, makes available both advance copies of. the Rus- sian journal and original glossy photographs and artwork. This serves to decrease the necessary time lag between publication of the original and publication of the translation and helps to im- prove the quality of the latter. The translation began with the first issue of the Russian joulenal. Editorial Board of Atomnaya Energiya: ,. 'Editor: M. D. Millionshchikov DeputY Director V. KurchEitov Institute of Atomic Energy Academy of Sciences of the USSR Moscow, USSR , Associate Editors:'N. A. Kolokortdov N. A. Vlesov. , #4 ? A. I. Alikhanov V. V. Matveev , ,A. A. Bophvar M. o. Meshcheryakov N. A. Dollezhal' P. N. Palei ' V. S. Fursov, l " V. B. Shevchenko I. N. Golovin' / D. L. ?SirtionerlkO- , V. F. Kalinin V. I. Smirnov , A. K. Krasin / ? ,' A: P. Vinogradov ? , A. I. Leipunikii, A. P: Zefirov 4 l , I 1 (Copyright 1972 Consultants Bureau, New `lark, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. No article contained herein 'May be reproduced for ani'purpose whatsoever Without permission of the publiehers. Consultants Bureau journals appear about six months after the publication Of the / , original Russian Issue. For bibliographic acCuracy, the English issue published by , Consultants Bureau carries the same number and date as 'the original Russian from which it translated. For example; a Russian issue ,published In Decem- ber will appear in a?Consult-ants Bureau English translation about the following June, but the translation issuewill carry the December date. When ordering any volume or particular issue of a Consultants Bureau journal, please -specify the 'date and, where appiicable, the'volume and issue numbers of the original Rueslan. The material you will receive will be a translation of that Russian volume or issue. , Subscription , $67.50 per volume (6 Issues) ? Single Issue: $30 2 4olurnes pe i year S s, Single Article: $15' (Add $5 for orders outside the United States end Cenede.) ? CONSULTANTS BUREAU, NEW yoRk AND LONDON 227 West 17th Street New York, New York 10011 Davis-House 8 Scrubs Lane ,Harlesden, NWI 0 6SE England Published monthly. Second-class postage paid at Jamaica, New York 11431. Declassified and Approved For Release 2013/03%01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 SOVIET ATOMIC ENERGY A translation of Atomnaya Energiya Translation published July, 1972 Volume 32,'Number 1 January, 1972 CONTENTS Engl./Russ. On the Stability of the Cans of Cylindrical Fuel Elements with an Initial Ellipticity ? Yu. I. Likhachev and V. V. Popov 1 3 Diffusional and Thermodynamic Properties of the 7-Phase of the System Uranium ?Niobium ? G. B. Fedorov, E. A. Smirnov, and V. N. Gusev 8 11 Deposition of Corrosion Products on the Surface. of Zirconium Alloys ? V. V. Gerasimov, A. I. Gromova, I. K. Morozova, V. N. Belous, A. S. Ilyukhin, C. A. Shchapov, L. G. Varnacheva, and G. P. Saenko 12 15 Mechanism of Reduction of Uranium Hexafluoride by Hydrogen ? Yu. N. Tumanov and N. P. Galkin 17 21 Calculation of Regular Systems of Neutron Absorbers ? Ya. V. Shevelev and I. L. Chikhladze 23 27 Thermalization of Neutrons in H20 at 318 and 77?K ? S. N. Ishmaev, I. P. Sadikov, and A. A. Chernyshov 29 33 Determination of Lithium in Solid Materials from the Reaction Li6(n, cx)H3 ? B. P. Zverev, Yu. F. Simakhin, and A. G. Dutov 35 39 Thermonuclear Combustion in a Bounded Region ? A. F. Nastoyashchii 39 43 Radiative Widths of U238 Neutron Resonances ? Kh. Maletski, L. B. Pikel'ner, I. M. Salamatin, and E. I. Sharapov 45 49 ABSTRACTS Variational Composite Methods of Calculating Neutron Distribution in Nuclear Reactors ? I. S. Slesarev, A. M. Sirotkin, and V. V. Khromov 48 53 Radioactivity of Metamict Zircons ? I. M. Lipova and G. A. Kuznetsova 49 53 Monte Carlo Calculations of Characteristics of Secondary Electrons Knocked Out from Various Materials by 7-Radiation ? V. V. Smirnov and A. V. Malyshenkov 50 54 The Kaon Factory ? a Two-Stage GeV) Isochronous Cyclotron ? L. A. Sarkisyan 50 55 Thermal Stability of Anhydrous Uranium Trichloride ? V. V. Rachev, L. A. Tarasova, and A. I. Pavlova-Verevkina 52 56 LETTERS TO THE EDITOR Adjoint Reactor Kinetics Equations: Delayed Neutrons Case ? V. V. Orlov 53 57 A New Procedure for Measuring Thermal Coefficient of Reactivity and Worth of Control Shim Rods in the IGR Reactor ? V. D. Lavrenikov 56 58 Redesign of the IRT-TM Reactor Dry Experimental Channels ? 0. F. Gusarov, V. V. Karnaukhov, and V. K. Leus 59 60 Critical Thermal Fluxes in the Boiling of a Eutectic Sodium?Potassium Alloy under Conditions of Free Convection ? V. I. Subbotin, D. N. Sorokin, A. P. Kudryavtsev, V. I. Brigutsa, and R. I. Zhirova 61 62 Measurement of Integrated Characteristics of Slow-Neutron Spectrum of VVR-M Critical Assembly? A. V. Nikonov and V. B. Klimentov 64 64, Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 CONTENTS (continued) Engl./Russ. Possibility of Measuring the Spectral Characteristics of a Neutron Flux using Direct- Charge Detectors ? V. S. Kirsanov, M. G. Mitel'man, N. D. Rozenblyum, E. N. Babulevich, V. A. Zagadkin, and Yu. M. Shipovskikh 66 65 Spectrometry of Low-Energy Ions by Surface-Barrier Silicon Detectors ? G. F. Bogdanov and B. P. Maksimenko 68 66 Measurement of Neutron Spectra with Threshold Detectors ? K. K. Koshaeva, S. N. Kraitor, and L. B. Pikel'ner 70 68 The Effect of Neutron Irradiation on the Operation of Surface Barrier Fission Fragment Detectors ? E. A. Seregina, N. N. Semenova, and B. D. Kuz'minov 73 70 The Effect of the Angular Dimensions of a Detector on the Error in the Determination of Certain Kinematic Characteristics ? G. N. Potetyunko 76 72 Visualization of Spatial Dose Distribution in a Fast Electron Beam? Yu. P. Vagin, G. L. Kabanov, Yu. A. Medvedev, and B. M. Stepanov 78 73 Spectra of Electrons Ejected in the Passage of Co60 Gamma Rays through a Two- Component Medium? L. V. Popova and L. B. Chegodaeva 80 75 Angular Distributions of Bremsstrahlung from 12-22 MeV Electrons as a Function of Target Thickness ? V. P. Kovalev, V. P. Kharin, and V. V. Gordeev 83 77 Matching of Accelerating Channels in a High Energy Proton Linear Accelerator ? B. I. Bondarev and L. Yu. Soloviev 86 79 Effect on Nonlinear Resonances on Beam Dimensions in the 70-GeV Accelerator ?V. I. Gridasov, K. P. Myznikov, and V. N. Chepegin 89 81 Value of from Energy Balance in U233 and Pu239 Fission? N. P. Kolosov, B. D. Kuziminov, A. I. Sergachev, and V. M. Surin 92 83 Absolute Measurements of the Quantity a for U235 and PU239 in the Neutron Energy Region of 10 keV-1 MeV? V. N. Kononov, E. D. Poletaev, Yu. S. Prokopets, A. A. Metlev, and Yu. Ya. Stavisskii 95 85 Chill-Casting Method of Bituminizing Natural Sorbents for Ir192? Kh. Daiev, G. Delchev, G. Gradev, S. Simov, and V. Zhelyazkov 98 87 INFORMATION All-Union Izotop Agency Serving the National Economy Exhibit at Exposition of Achievements of the National Economy ? V. A. Dolinin 101 91 Seminars and Conferences at V/0 Izotop 104 93 CONFERENCES Sixth All-Union Conference on Synthesis, Production, and Applications of Scintillators ? L. Ya. Zhil'tsova, E. N. Matveeva, and I. M. Stoletova 106 94 Fourth Conference of the International Nuclear Data Committee ? M. F. Troyanov 108 95 International Conference on Elementary Particles ? I. A. Savin 110 96 Fourth International Conference on Plasma Physics and Controlled Nuclear Fusion ? B. B. Kadomtsev and V. D. Shafranov 113 98 BRIEF COMMUNICATIONS 118 101 The Russian press date (podpisano k pechati) of this issue was 12/17/1971. Publication therefore did not occur prior to this date, but must be assumed to have taken place reasonably soon thereafter. Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 ON THE STABILITY OF THE CANS OF CYLINDRICAL FUEL ELEMENTS WITH AN INITIAL ELLIPTICITY Yu. I. Likhachev and V. V. Popov UDC 621.039.54 The fuel-element cans of gas-cooled and water-cooled reactors are subjected to a fairly high external pressure due to the coolant (sometimes exceeding 100 atm). The cans are thus in danger of losing stability, possibly leading to the collapse of the compensation volume or to the formation of a longitudinal corruga- tion in the parts of the can resting on the heat-emitting core. The stability of the cans of cylindrical fuel elements was studied earlier [1-4]; however, no allowance was made for either the initial ellipticity of the can or the creep of the material of which it was composed. The creep of cylindrical cans with an initial ellipticity was considered (with various simplifying as- sumptions) in [5-7], but without allowing for the influence' of the thermal flux, the swelling of the steel, and the changes taking place in the temperature and pressure during deformation, which are important factors in the cans of fuel elements. Let us consider the creep of a cylindrical fuel-element can having an initial ellipticity w1 = Ivo cos 20 subjected to a time-varying excess external pressure q(t) and a thermal (temperature) field T(t, z), where w0(0) is the radial deviation of the middle of the surface of the can from the ideal circular form and z is the distance from the middle of the surface. The process of can deformation develops as time progresses in a series of short stages [8]. Let us suppose that at the n-th stage of deformation Ant = tn? tn_i the stresses, strains, and displacements have received increments Ancr, Ane, Anw, Anv. ?The increments in the stresses should satisfy the following equilibrium equations n/2 6/2 TERAng= ?4 Anax dz de; (1) .c 0 ?6/2 6/2 RAnq = ? 6,?cro dz; (2) ?6/2 8/2 = ? Ancrozdz, (3) ?6/2 where AnM = AnMe Rwn-tAncl + RqnAnw is the increment in the bending moment; Anq = qn? cin...1 is the increment in the constant component of the bending moment; qn_land qn are the pressures at the beginning and end of the deformation stage. In accordance with the "rigid-normal" hypothesis (Levi?Kirchhoff) and the assumption of plane de- formation, we have [9] the following for the strain increments A?ce = zA?x; Anc?=Ane = const, where Anc(10, An) are the increments in the circumferential deformation and the curvature of the middle of the surface: (4) A . r_d ono Aniv ; do Ax 7Ccr (12,-(A?w)-F (A?w). (5) Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 3-9, January, 1972. Original article sub- mitted December 8, 1970. C 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Let us write down the physical relationships between the stresses and strains in the form [8]; A?co = 4_A?(50_1 Ana. + T3-I AnS aAnT ? (4(n)) Ant; Ane. = T A?crx - Ancro AnS f. aAnT ((n)) Ant. (6) The elastic modulus E, the Poisson coefficient II, and the thermal expansion coefficient a are taken as con- stants (defined for a certain mean temperature); this may be justified from the following considerations. During the operation of the reactor at normal load the can temperature usually varies little, so that the average values of the characteristics in question may be used for practical calculations. In considering transient processes (when the reactor is just coming up to power) the deformation of the fuel-element can is calculated in short time stages, starting from a temperature Tn (characteristic of the particular can ma- terial) at which creep deformation becomes appreciable (for example, in 1Kh18N9T steel, from Tn 500?C). In the temperature range Tn - Tmax it is permissible to average the quantities E, 12, and a (for 1Kh18N9T steel the working temperature Tmax 650?C). The quantity ,AnS determines the swelling of the can mate- rial during the n-th stage of loading: AS=Sn (z)-S_1 (z). The swelling of the steel is determined [10-12] by the integrated neutron flux it (neutron energy E> 0.1 MeV) and the temperature level: the temperature dependence may be written S=AncI)'L (T), _ Qs Q: L (T) e RT ? B se RT? The creep deformations are determined by the expressions (2ao oc; For the theory of strengthening [13] where Q9 (PC (c1, T, ej). .43e- 7ere?H(e?Vi,13( 7?)? ec {.t.? H (7') for the stage of transient creep, [I (e7) = H (7') for the stage of steady creep; - A4e "2. Gy- ) is the deformation at the beginning of the stage of steady creep; A3 and A4 are experimen- tal coefficients; Q3 and Q4 are the activation energies of the creep process; m3(T), m4(11, H(T) are certain functions of temperature, sci- dt is the accumulated creep deformation; def = (f2 /3) ji (deco - dex)2 7, d4)2 (d4- d4)2 is the intensity of the differentials of creep deformation; ai=l/a-- - axao is the intensity of the stresses. From the condition of the elastic change in volume dc= - d6- decx. (9) The increment in temperature in the range tn to tn_i may be found from the expression A, T (z) = 7' (tn, z) -7 (tn-1, z); (10) (7) (8) ( c(n)) is a certain mean value, of the function c(ri) in the temperature range in question, refined by the meth- od of successive approximations. In the first approximation, the function c(ri.) is determined from the stresses in the previous (n - 1)-th stage of loading (en) )= Thena_i the stress increments and the value of the function [) e ] at the end of the stage of deformation are determined. (n In the second and subsequent approximations we take (11) 2 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 the calculation being continued until the values of the function (e(n)) obtained in the previous and following stages are sufficiently close. The symmetry conditions should also be satisfied: dAnu: = ; d4nw 0 = 0; dO 0-0 dO Any lo=o ---- 0; Any = 0 and also the initial conditions for the stresses: aj (0, z) o-jo (0, z) (j x, 0), (12) (12a) where o-jo(O z) are the stresses in the can at the onset of the deformation process. Solving the system of Eqs. (1)-(12): A?o-, 1 .Ett, [OA p.A?.xz Anel ? (1 A ?.S A?uo [ e(6 ! RA?d + xz ? (1 -1- p.) aA?T - (1 1.t) 3 A?e6 , where Anec , An< are the increments in the creep deformations: (e(n)) Ant; AnEfs'?= (n)) A?t; A/2 6/2 6/2 6/2 2 1 A---- -- .-T .0 C AX,d0 dz 1-2p, .7? ,_i_ An ceo r 2E b .1 I. A?T dz -f -F36. C A?S dz; 6/2 6/2 n/2 6/2 6/2 6/2 A ,, . E a dz+ t? f AX, dz ? --L2 .0 C A?e,:cv dO dz 2-11 A, ti T f A?T dz-'r-- C AnS dz; 2E 6, ' . 36 -.6/2 -.6, 0 -7.6/2 -.672 -.6/2 6/2 6/2 6/2 6/2 12 12u 63 C A?Tz dz ; 4 (16;1 ? C A?Sz.dz 3A?)II . Anx --- --- C ,6,?6z d.z -1- --,-- C A?e..z dz ; ? 63 12a (1+11) 63 yeto ' ?.6/2 ?.6/9 . ?.6/2 ?.6/2 . 6/2 5/2 Anill, ? e I- bo/2. _i C0RA 632 , 4 (1-17 0 H2 12a (1.,1- it) R2 C A?Tz dz 1 ; 1 2 , 63 J 00 con A,,w==E b.; cos 2/0 ; A/2 12/n ,c bi = 4 jA2 F(0) cos 2j0 d0; 2 0 n/2 a/2 C0=--Ano; b? F(0)dO; A2 =- (1-1- 3qn ) ; F (0) = A?q e ge 6/2 ' ? 4 R2 C A ?E'6z dz [1, A?e!.;:z dz (13) (17a) Relations (13)-(17) enable us to calculate the increments in the stresses at each n-th step in time if we know the stresses at the end of the (n? 1)-th step, the functions V (n) being refined by the method of suc- cessive approximations. In considering the process in which the reactor is coming up to power, the stresses in the can are determined from the following relationships for the initial stage of deformation (t = to): (Teo (0, z) ? q (to) 12611:0 Z [T7,? T (t, z)]; ' -- lig (10) 12Mo (Tx? (0, 26 tt ea Z IT,,--(1, z)I. t (18) Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 69, kg/cm2 120 100 80 60 ?40 20 0 -20 -40 -60 -80 -100 -1200 -1400 -1600 -1800 Fig. 2. Stress distribution over the cir- cumference for various periods of opera- tion of the fuel element: 1) t = 0; 2)t=60 h; 3) t = 120 h; 4) t = 180 h; 5) t = 240 h; 6) t = 300 h. I42 45 fir d/ rr 0,3 42 , f , -1600 l -8 0 -6 0 -400 - 200 200 400 500 800 1000 1200 59, 140Q kg/cm` 0,1 0,2 43 44 15 Fig. 1. Stress distribution over the thickness of the can for various periods of operation of the fuel element: 1) t = 0; 2) t = 60 h; 3) t = 120 h; 4) t = 180 h; 5) t = 240 h; 6) t = 300 h. 7 6 7 7 7 7 7 41 42 0,3 44 0,5 , 48 49 100 4 i FAN 44 MORINO lik riper where M0(0) = q(to)R (w2 + wi) is the bending moment in the cross sections of the can with an initial ellipticity w1 (0): which, as a result of the application of the pressure q(to), acquires the additional curvatures [14]: w2 (0) -- w? cos 20, ge.q ltol ?1 (19) where qe =[E(T11)/4(1 ? iA2)](6/11)3 is the critical pressure for an ideally circular tube; to is the time within which the average temperature of the can becomes equal to the charac- teristic temperature corresponding to the appearance of creep T. A dangerous state of the can may occur for the following reasons. 1. For ductile material, the creep-engendered in- crease in the sag and the bending moments has the effect that the intensity of the stresses in most stressed cross sec- tion of the can reaches the yield stress: a, (1, 0, -i- 6/2) = o (T, (20) which may be regarded as the onset of the loss of stability (owing to the small thickness of the can). Here we allow for the change in the yield stress of the can material arising from changes in temperature and the effects of irradiation, the quantity n (t) determining the radiation damage accumu- lated during the operation of the can (for example, this quan- tity may be given by the dose of radiation or by the num- ber of displaced atoms in the can material [15]). 2. For an ideally elastic material, at a certain critical time tk the sagging of the can increases sharply and a loss of stability sets in. 3. The can material accumulates damage arising from the prolonged action of stresses at high tem- peratures, which may cause the appearance of cracks and break the air-tightness of the fuel element before the can loses stability. In this case the working efficiency is determined by the criteria of long-term strength or long-term ductility. 4 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 3000 2500 2000 1800 1500 1000 50 wI8 72 10-I 10-2 / ii1 ? / 1 I / A I 2 3 / . 1 / /12 I 4 /8 / lc- / GT I 10-4 1 /tia , . i 10 , 10-6 --. ..--"-... ' / .1/ / / / . ? - 7 wa....._..z_.--__ .... ___ --- .-:-_. ??????? ?????? ....? .... ..... _.- ...-? ...." / ????? ..???? ?????? .....- ?????? ..... ..- ."- ?????? .....- ..., ..-- .?-? ???? ? / / 60 48 35 12,t 0,12 50 120 180 .240 SOO 350 'fr20 480 t, h Fig. 3. Time changes in the intensity of the stresses (curves 1-4), the maximum sags (curves 5-8), and the total damage to the can material (curves 9-12) in the most-stressed parts of the can for different values of the original ellipticity: 1, 5, 9) wo = 0.01; 2, 6, 10) woA5 = 0.007; 3, 7,11) wo/O = 0.005; 4,8,12) w01/45 = 0.002. 4. If, as a result of the increase in ellipticity, the can closes the gap and rests on the fuel core, there may be an irreversible increase in the length of the can in the course of heat exchange (thermomechanical rachet) [16]. The time tx required for the onset of this mechanism may be determined from the condition where r(t) is the change in the radius of the core due to swelling. We used the foregoing theory in conjunction with an electronic computer (the M-20) in order to cal- culate the stability of austenitic steel fuel-element cans for a gas-cooled fast reactor. Figures 1 and 2 show the thickness and circumferential stress distributions in a can with dimensions of (5/It = 0.14 and an initial ellipticity of NA = 0.01 for various periods of operation of the fuel elements, the can being subjected to a pressure of q = 130 atm at 670?C (the temperature drop along the wall is taken as zero). The changes in the maximum sags, the damage to the can material, and the stress intensities at the most stressed points are shown in Fig. 3 as functions of time for the same temperature and pressure and for various values of the initial ellipticity (w0/5 = 0.01? 0.002). The dangerous state of the can for all w01/45 was determined by the appearance of plastic deformations (ci = CT); on reducing w0/6 (from 0.01 to 0.002) the time to the onset of the loss of stability tk increased (from 323 to 535 h). For all values of the initial ellipticity considered, the maximum sag at the instant of reaching the dangerous state equals wo/O 0.36, while the damage factor a 1.4 ? 10-2. Curve la in Fig. 3 shows the time variation in the stress intensity for the case in which the temperature drop along the wall equals A = 30?C. The initial fall in the curve is due to the relaxation of the thermal stresses arising from the drop A. The time of operation of the can before reaching the dangerous state was greater in the presence of a temperature drop than in the A = 0 case. Figure 4 shows the effect of a reduction in the excess exter- nal pressure, resulting from the accumulation of gaseous fission products under the can, on the loss of can stability (NA = 0.01, T = 670?C). The time to the onset of can stability loss increases from 323 h (for 5 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 , kg/cm2 2000 1800 1500 1000 6 I? 7' I 14 500 --c 0,1 02 3 4 5 10 20 30 40 50 60 708090100 200 300 400 5006007008001000 t,h Fig. 4. Effect of changes in temperature (curves 2, 3) and pressure (cruves 4, 5) on the loss of can stability: 1) q = const, T = const; 2) temperature increases by 0.3?C in 1 h; 3) temperature increases by 0.2?C in 1 h; 4) pressure falls from 130 to 0 atm in 104 h; 5) pressure falls from 130 to 0 atm in 103 h; 6, 7) system passes to nominal power in 0.2 and 5 h respectively. a constant pressure of q = 130 atm) to 356 h if the pressure falls linearly from 130 to 0 atm in 104 h. The can does not lose stability at all lithe pressure falls from 130 atm to zero in 103 h. The same figure illus- trates the effect of a change in the temperature of the can (w0/05 = 0.01, q = 130 atm) while the reactor is working at nominal power on the loss of stability. If the temperature rises linearly by 20?C in 100 h, the time to the onset of stability loss falls from 323 to 132 h; for a temperature rise of 30?C in 100 h the time falls to 107 h. The change in the stress intensity for two transient modes (reactor passing to nominal power in 0.2 and 5 h with a constant external pressure of q = 130 atm and wo/O = 0.01) is illustrated in Fig. 4. In the case of the rapid transient mode, creep is unable to develop, the sagging is slight, and the can fails to reach the dangerous state. For the slow passage to nominal power creep does occur, leading to substantial sag- ging, and the dangerous state correspondingly arises (cri = We may thus draw the following conclusions. 1. We have found a solution to the problem of the stability of a cylindrical fuel-element can in the creep stage, allowing for the initial ellipticity and also accounting for changes in the pressure (due to gas- eous fission products) and temperature during service. 2. The use of the theory of strengthening and the solution of the problem in terms of increments en- able us to discuss the stability of the can in the transient modes of reactor operation. 3. In the solution we allow for the effect of the nonuniform swelling of the steel, such as may occur for large integrated fluxes in fast reactors, on the loss of stability of the can. 4. The results of our calculations show that the time to the onset of can stability loss is considerably affected by the initial ellipticity of the can, by any fall in excess external pressure, and by any change of temperature. LITERATURE CITED 1. E. Clukler and E. Passig, Nucl. Eng. and Design, 7, No. 3, 236 (1969). 2. D. Howl, J. Brit. Nucl. Energy Soc., 4, No. 4, 337?(1965). 6 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 3. K. Ward, J. Brit. Nucl. Energy Soc., 4, No. 4, 354 (1965). 4. D. Howl, J. Brit. Nucl. Energy Soc., No. 2, 103 (1969). 5. N. Hoff, IASS, No. 26, 663 (1959). 6. B. Sandstrom, Trans. Roy. Inst. Technol., Stockholm, No. 115 (1957). 7. T. Wam, J. Franklin Inst., 272, No. 1, 138 (1961). 8. I. A. Birger, Izv. Akad. Nauk SSSR, Mekhanika, No. 2, 113 (1965). 9. I. A. Birger, Circular Plates and Shells of Rotation [in Russian], Oborongiz, Moscow (1961). 10. S. D. Harkness and Che-Yu-Li, Symposium on Radiation Damage in Reactor Materials, Vienna Tuns (1969), Sm-120/F-4. 11. S. Oldberg and D. Sandusky, Trans. ANS, 12, 588 (1969). 12. U. Wolf and A. Withop, Trans. ANS, 12, 114 (1969). 13. B. F. Shopp, in: Strength and Deformation in Nonuniform Temperature Fields [Russian translation], Gosatomizdat, Moscow (1962). 14. S. P. Timoshenko, Stability of Elastic Systems [Russian translation], Gostekhteorizdat, Moscow (1955). 15. W. Sheely, Nucl. Sci. and Engn., 29, No. 2, 174 (1967). 16. E. Duncombe and I. Goldberg, Nucl. Applications and Technol., 9, No. 1 (1970). 7 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 DIFFUSIONAL AND THERMODYNAMIC PROPERTIES OF THE y-PHASE OF THE SYSTEM URANIUM ? NIOBIUM G. B. Fedorov, E. A. Smirnov, UDC 539.219.3:669.822 and V. N. Gusev Alloying of uranium with refractory metals having a bcc lattice improves the mechanical and core- rosion resistance properties of the uranium, and is one of the principal ways of coping with radiation swel- ling. The effect of the alloying elements on resistance to swelling can be estimated with the aid of data on self-diffusion of the components in alloys of uranium with refractory bcc metals. A decrease in the self-diffusion coefficients of Y-uranium as molybdenum, zirconium, and niobium are added had been re- ported earlier [1]. But later on it was demonstrated that alloying with zirconium actually increases the self-diffusion coefficients of uranium, and only combined alloying of uranium with both zirconium and nio- bium (in a ratio of 1: 1 at. %) results in an appreciable loss of mobility on the part of the uranium atoms. Bulk diffusion coefficients of uranium and niobium in uranium alloys with niobium contents of 5, 10, 20, 35, 50, 65, 80, and 90 at. %were determined in this work. These investigations were carried out over Ig 9 -10 11 -12 -13 -10 -11 12 -13 1900 1600 1400 1200 1000 ?C 1 ??,."'',,,/ , a , \ i ?\&0 9 8 7 6 -...? b 4 3 2 --.:?....1 \NZ.Z*i \ \ \ \ 9 8 765 4050 60 ,0 8010" Fig. 1. Temperature dependences Of the diffusion coefficients of Nb 99 (a) and U235 (b) in uranium?niobium alloys: 1) Pure uranium; 2) 5 at. % Nb; 3) 10 at. Nb; 4) 20 at. % Nb; 5) 35 at. % Nb; 6) 50 at. % Nb; 7) 65 at. % Nb; 8) 80 at.% Nb; 9) 90 at. % Nb; 10) pure niobium. the temperature range from 930? to 1900? C, using the ra- dioactive isotopes U239 and Nb95 and the method of stripping off layers and measuring the integrated radioactivity of the remainder of the specimens. The alloys were prepared by arc remelting from electron-beam niobium and electro- lytic uranium. The specimens, as remelted, were subjected to phase recrystallization followed by a homogenization anneal, with the purpose of eliminating the cast structure. The procedure followed in measuring the bulk diffusion coefficients of uranium and niobium has been described in an earlier article [2]. The temperature dependences of the diffusion coefficients of uranium and niobium are cited in Fig. 1, and the values of the diffusion parameters of the components appear in Table 1. Alloying of uranium with niobium brings about a considerable fall-off in the self- diffusion coefficients of the components. For example, when uranium is alloyed with niobium in amounts from 5 to 20 at. %, a decline in the self-diffusion coefficients of uranium is observed in the range of investigated temperatures, to the extent of 15 times and 50 times respectively, and this is found to be in excellent agreement with the earlier reported findings [1] . Alloying of the uranium has practically no effect on the en- ergy of activation of self-diffusion when the niobium content is as high as 20 at.%. But any further increase in the alloying ele- ment (to 35 at. % Nb, say, or higher) brings about a significant rise in the energy of activation of diffusion on the uranium and the niobium. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 11-14, January, 1972. Original article submitted November 23, '1970; final revision submitted April 12, 1971. _8 C 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 1. Diffusion Parameters of Components in 'y-Phase of System Uranium?Niobium Diffusion Niobium content, at.% I parameters 0 5 10 20 j 65 80 90 100 Q. kcal/g 36,0 34 35,2 39,6 53,2 57,2 65,6 ?67,0 73,0 76,7 atom [5] [6] U236 D0, cm2/sec 1,1.10-4 3,2.10-5 3,5.10-6 10-5 1,25.10-4 2,5.10-4 4,0.10-3 6,3.10-4 2,5.10-3 6,5-10-6 151 [6] Q. kcal/g 28,5 -- -- 68,8 72,7 77,5 91,5 100,6 100,6 atom [21 171 rib95 D10 ,cm2/sec 1,2.10-5 -- -- -- 3,1.10-2 3,1.10-2 7,6.10-2 1,1 5,2 0,91 [2] [7] IT Ig Du Nb A-14 Av -13 ?i Al2 Ai! A 10 Agif.4:1dAYIA t44 9 ATATATAT-irV 11 Nb Zr Zr Nb Nb Nb 80 7 t2,.t2,.0 .Z AIL AVM. A N. IS0 AVATA %AV AVATAvAill 50 A74 Vkk "*A742%, Af A %Ta WO 0140 u itSltzrirv.747,2fik Zr Fig. 2. Isolines of coefficients and of energies of activation of diffusion of compo- nents in the system U?Nb?Zr at 1100?C. A familiar procedure [4] was enlisted to provide a comparison in studying the effect of niobium alloy- ing on self-diffusion of uranium in the a-phase at temperatures in the range 550-630?C. Introduction of as little as 2 at.% niobium lowers the bulk self-diffusion coefficient of a-uranium by about three times. It must be borne in mind that self-diffusion in pure uranium takes place in the supersaturated vacan- cies of the matrix [5, 8, 9]. This makes it perfectly clear that the self-diffusion parameters of uranium and the diffusion parameters of the vacancies are closely similar. The decline in the self-diffusion coeffi- cients of the components as uranium is alloyed with niobium unquestionably improves resistance to swelling, inasmuch as the basic transport process at work in the volume-diffusion mechanism of the motion of voids is the movement of vacancies from one position on the surface of the void to another through the surrounding host matrix [10]. On the basis of the results obtained and findings published earlier [2-4, 11], isolines of the diffusion coefficients and energies of activation were constructed at 1100?C in the case of the system uranium?nio- bium?zirconium (Fig. 2). The concentration dependences of the diffusion characteristics in the uranium ?niobium part of the ternary diagram show satisfactory agreement with diagrams of the solidus tempera- ture [12] and with hardness and creep diagrams [13] of alloys belonging to the system uranium?niobium ? zirconium in the y-state, which provides experimental proof of the existence of some correlation between the diffusion characteristics of the components and refractory behavior. This lends added interest to investigations of interdiffusion in the system uranium?niobium, since the interdiffusion parameters characterize to an even greater extent the refractory properties of the alloys [4]. The interdiffusion coefficients were calculated on the basis of Darken's formula [14]: -15=(DT.T2+ Mxi)(1-1- algti aigxi ' Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 (1) 9 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 0,8 44 0,2 0 \ \ \ 1 \ \ \ // / / 2 N lt\ A/.., A 3 / / \MMIWppp \ \ \ \ \ Li 20 40 60 ? 80 Nb at. 04, 4 where D:1` is the diffusion coefficient of the i-th component, measured with the aid of radioactive isotopes; xi is the concentration of the i-th component; fi is the coefficient of thermodynamic activity coefficient. The thermodynamic properties of the system were 3? studied by the method of measuring the electromotive forces (emf) of the concentration cells [3] over the tem- perature range from 750? to 900?C using, as one of the electrodes, uranium alloys with contents of 5, 11.7, 20, 32, 47, 72, and 87 at.%Nb. Temperature dependences of the emf of a concentration cell of the type U (solid) U+3-,- (KC1? NaC1)1U? Nb (alloy). were obtained. The potential-building process in the cell is uranium transport. The thermodynamic activities of uranium were found from the formula 2 1 Fig. 3. Thernodynamic properties ofr the system U? Nb at 1000?C; 1) uranium ac- tivity; 2) niobium activity; 3) thermody- namic multiplicative factor. Ig LJ -8 -10 -12 -14 16 -18 \ \ -1 \ \\I 11111111 \ r El.ffl Kg \ 1 11 20 40 60 at. efo Nb Fig. 4. Concentration dependences 'of coef- ficients and of energies of activation of inter- diffusion in the system U? Nb at 1000?C: 1) D [15]; 2) to [present article]; 3) Q [15]; 4) Q [present article]. 80 Nb Qin , kcal/g- atom 120 ZuEF Ig a== 2.3/1? 15,120?E 7' T ' (2) where Zu is the valence of the uranium; F is the Faraday number; E is the cell emf. As earlier [3], the valence of uranium was assigned the value three. The activity of the niobium was calcula- ted by graphical integration of the Gibbs? Duhem equation: XU 1g au 1g aNb ? dxu ? ? ig au. Nb a-Nb (3) Results of the calculations are plotted in Fig. 3. Recalling that fu = au/xu, we calculated the values 100 of the thermodynamic multiplicative factor in Eq. (1) from the concentration dependence of the emf: a ig fu 15,120 BE fl =i ig d1g alj (4) xU The concentration dependence of the thermodynamic 60 multiplicative factor is also plotted in Fig. 3, for 1000?C. The negative deviations of the thermodynamic ac- tivity of the components from ideal behavior is evidence, 40 as an examination of the thermodynamic properties of the system uranium?niobium clearly argues, for strength- ening of the interatomic bond in they-solid solution. 20 On the basis of Darken's equation (1), the interdif- fusion coefficients D were determined for 1000?C (Fig. 4). The concentration dependence of the energy of ac- tivation of interdiffusion Q was calculated under the as- sumption that the temperature dependence of D is of the form (5) The interdiffusion coefficients in the system uranium?niobium were determined by other authors [15] using the Matano method. Concentration dependences of the energies of activation Q and of the interdiffu- sion coefficients D converted to 1000?C values are plotted in Fig. 4. The predicted and experimentally determined interdiffusion coefficients in the range of niobium concentrations 50-100 at.% Nb are clearly 10 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 satisfactory agreement in Fig. 4. A slight discrepancy in the interdiffusion coefficients in the uranium-rich region might be due to anomalies in the uranium diffusion characteristics stemming, in our opinion, from supersaturation of the matrix with vacancies [5, 8, 9]. The resulting concentration dependences of the energy of activation of interdiffusion are in satisfac- tory agreement with published data [15], except for the 80-100 at.% Nb region, where the published values of the energies of activation are seen to be much higher. Consequently, the rise in the energy of activation and the lowering of the interdiffusion coefficients accompanying alloying of uranium with niobium provide evidence on increased refractory strength which, as stated earlier, must have the effect of also enhancing the resistance of the alloys to gas swelling. LITERATURE CITED ? 1. Y. Adda and A. Kirianenko, J. Nucl. Materials, 6, 135 (1962). 2. G. B. Fedorov, E. A. Smirnov, and V. N. Gusev?, At. Energ., 27, 149 (1969). 3. G. B. Fedorov and E. A. Smirnov, At. Energ., 21, 189 (1966).- 4. G. B. Fedorov, E. A. Smirnov, and F. I. Zhomov, in: Physical Metallurgy and General Metallurgy of Pure Metals, No. 7 [in Russian], Atomizdat, Moscow (1968), p. 166. 5. G. B. Fedorov and E. A. Smirnov, in: Physical Metallurgy and General Metallurgy of Pure Metals, No. 6 [in Russian], Atomizdat, Moscow (1967). p. 181. 6. G. B. Fedorov et al., At. Energ., 31, 516 (1971). 7. G. B. Fedorov, F. I. Zhomov, and E. A. Smirnov, in: Physical Metallurgy and General Metallurgy of Pure Metals, No. 8 [in Russian], Atomizdat, Moscow (1969), p. 145. 8. G. B. Fedorov, E. A. Smirnov, and F. I. Zhomov, in: Physical Metallurgy and General Metallurgy of Pure Metals, No. 5 [in Russian], Atomizdat, Moscow (1966), p. 92. 9. G. B. Fedorov, E. A. Smirnov, and S. S. Moiseenko, in: Physical Metallurgy and General Metallur- gy of Pure Metals, No. 7 [in Russian], Atomizdat, Moscow (1968), p. 124. .10. P. Shewmon, Trans. Met. Soc. AIME, 230, 1134 (1964). 11. G. B. Fedorov, E. A. Smirnov, and S. M. Novikov, in: Physical Metallurgy and General Metallurgy of Pure Metals, No. 8 [in Russian], Atomizdat, Moscow (1969), p. 41. 12. E. M. Tararaeva et al., Theoretical and Experimental Methods for Investigating Phase Diagrams of Metallic Systems [in Russian], Nauka, Moscow (1968), p. 266. 13. V. A. Bugrov and 0. S. Ivanov, Physical Chemistry of Thorium?Uranium Alloys and Refractory Compounds [in Russian], Nauka, Moscow (1968), p. 86 and 92. 14. L. Darken, Trans. AIME, 175, 184 (1948). 15. N. Peterson and R. Ogilvie, Trans. AIME, 227, 1083 (1963). 11 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 DEPOSITION OF CORROSION PRODUCTS ON THE SURFACE OF ZIRCONIUM ALLOYS V. V. Gerasimov, A. I. Gromova, I. K. Morozova, V. N. Belous, A. S. Ilyukhin, G. A. Shchapov, L. G. Varnacheva, and G. P. Saenko UDC 620.197.1 The purpose of this work was to obtain experimental results and to generalize the literature data on the amount of deposits on the surface of zirconium alloys as a function of the composition of the medium, time of exposure, and temperature of irradiation. For the investigation we used plate samples of zirconium alloys [1) with 1% niobium; 2) with 2.5% nio- bium; 3) system Zr?Sn? Fe; 4) system Zr?Ni? Fe; 5) system Zr?Nb? Cu] with dimensions 50 X 20 X 1 mm. For each time exposure we tested three to five parallel samples. The tests were conducted under static and dynamic conditions. After the experiments iron was washed off the samples with a hot solution of hydrochloric acid (1:1) and analyzed by a chemicoanalytical method. The details of the method of con- ducting the tests were described earlier [1]. The experimental data in the literature on the deposition of corrosion products on the surface of con- struction materials are extremely scanty. The available indications pertain to general considerations of K, g/m2. day 0,10 0,08 go5 0,04, go2 3 2 01 0 02 g4 06 08 40 [F81 mg/kg Fig. 1 0 5 lp 2 ?A/cm 1 1 4 6 810112 4 6 8104 2 4 K, g/m2. day Fig. 2 Fig. 1. Rate of deposition of corrosion products K of steels on con- struction materials under static conditions in water at 300?C (in 100h of tests): 1) on a zirconium alloy with 2.5% niobium; 2) on a nickel al- loy (N-1); 3) on a titanium alloy (VT-1-2). Fig. 2. Rate of deposition of corrosion products of steels on construc- tion materials in water at 300?C: 1) on zirconium alloy; 2) on titanium alloy; 3) anodic polarization on alloy of zirconium with 2.5% niobium. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 15-19, January, 1972. Original article submitted December 14, 1970; revision submitted February 14, 1971. 12 C 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 the possible pathways of accumulation of corrosion products in the system and their subsequent deposition on the surface of the materials. In [2, 3], in particular, a predominant deposition of corrosion products on stainless steel in comparison with zirconium alloys is mentioned. The authors of [4] note that the cor- rosion products of the circuit are more firmly retained on stainless steel than on zirconium alloys, attrib- uting this phenomenon to different models of growth of the oxide film? inward and outward. It was shown in [1] that the absolute value of the deposition of corrosion products on a zirconium al- loy (under static conditions in water at 300?C in the absence of a heat flow) is lower than on alloys of tita- nium and nickel. It was reported in the same work that the value of the deposits on the surface of the ma- terials was 0.01-0.1 g/m2 day, depending on the concentration of the corrosion products in the system. The rate of deposition of corrosion products of iron on a zirconium alloy with 2.5% niobium has a concentration dependence similar to that of the corrosion products in water (pH = 7) under static conditions (Fig. 1). In water with an iron concentration of 0.1-0.3 mg/kg, the rate of deposition on a zirconium alloy does not ex- ceed 5 .10-3-7 .10-3 g/cm2. day (see Fig. 1). In- creasing the iron concentration in the water from 0.3 to 0.7 mg/liter leads to a substantial increase in the rate of deposition on all three materials. TABLE 1. Rate of Deposition of Corrosion Products of Steels on Alloys of Zirconium, Titanium, and Nickel Medium on con- tent in solution, mg/liter Rate of deposition ? 103 g/m2. day alloy of zirconi- iml yit1.1 ',1121111- 6 3,6 32,4 32,0 on nickel alloy 8,4 8,48 116 ? on ti- tanium alloy 6,0 6,0 42,2 102 Distilled water pH ?,--:,6,6,[02] 5 0,025 mg/liter 0,12 0,27 0,72 1,0 Distilled water, pH =10 (NH4OH), [02] 5 0,025 mg/liter , 0,5 7,8 16 14 Distilled water, pH = 3 (HNO3), [02] 5 0,025 mg/liter 0,12 0,24 8 23,5 25 11,3 29 12,8 Distilled water, pH .?-?.6,6, [02]A.-, 2-3 me /liter 0,12 6,32 9,74 6,57 The change in the composition of water may be the cause of the change in the rate of deposition. It is known [5, 6] that the oxygen concentration in wa- ter and the pH value may influence not only the con- centration of the corrosion products in the system, but also their dispersed composition [1], and, con- sequently, the amount of deposits of the corrosion products on the surface of the materials. When the pH value is increased from 6.6 to 10 (at comparatively close values of the concentration of corrosion prod- ucts under static conditions), the rate of deposition on the zirconium alloy with 2.5% niobium decreases, while it increases with increasing pH up to 3 (Table 1). Increasing the oxygen concentration in the me- dium from 0.02 to 3 mg/kg practically does not in- fluence the rate of deposition of corrosion products on the zirconium alloy at the same concentration of corrosion products in water (see Table 1). The rate of deposition on the zirconium alloy depends substan- tially on the time: with increasing time of exposure the rate of deposition drops, both under static conditions TABLE 2. Dependence of the Rate of Deposition of Corrosion Products on a Zirconium Alloy with 2.5% Niobium on the Time Static conditions Dynamic conditions medium time of testing, h rate of depo sition? 10-3 g/m2. day Desalted deaerated water, pH= 10 (NH4OH), t= 300C 100 300 25,1 1,58 Desalted deaerated water, pH t= 300?C 100 300 500 7,8 1,6 0,6 medium time of testing,h rate of depo- gs mi o2n. day 10 3, Steam?water mixture. pH [0d= 0,02 mg/liter (in water), [Fe=0,02 mg/liter, *t = 285?C, rate of flow v p.-?,?61 m/sec ? 2600 9300 1.3 1.8 Moist steam, pH rate of flow v = 20 m/sec 1500 3000 6700 1,7 0,46 0,13 The iron concentration in the water of the circuit increased to ?2 mg/kg during the testing. 13 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 3. Influence of Irradiation on the Rate of Deposition of Corrosion Products of Iron on Zirconium Alloys Alloy No. Medium Rate of movement of coolant, m/sec Time of t t esing, h Intensity of neutnonflux,deposition neutrons' /sec Rate of .1073 g/rnz ? day Color of film 1, ?C pH [021, mg/kg [Fel, mg/kg 2 220--240 -- 6.5 0,1--0,5 -- 0,1 up tol 3500 ?1013 - 0,33 Black 3 280 -- 6,5 ?0,5 up to0,1 -- 3450 I -- 0,139 . 3.1013 0,765 Dark gray 4 280 --6,5 --0,5 up to0,1 __ 3450 { -- 0,486 Black 3.1013 1,25 Light gray 330 9-10 0,02 0,05 4 5500 {-- 0,56 Black 1013 0,52 . TABLE 4. Deposition of Corrosion Prod- ucts on Zircalloy Jackets of Fuel Cells in the Loop of the NRX Reactor, Cooled with a Steam ?Water Mixture 6] (t = 285?C) Concentra- tion of cor- rosion.prod- uctsin cool- ant, nig/kg Thermal flux on surface, 1A//crn2 Temper- ature o,f jacket ' oc Time. Deposi-, ofizs-z ? days /cm2 RAte ?! A' g/rn clay 0,035 0,006 0.005 .0,005 0,003 0.003 100 70 68 66 62 58 295 295 550 295 ' 290 400 16 65 5 5 32 32 200 150 4 5 5 4 125 23 8 10 ? 1,56 1,25 ? and under dynamic conditions (Table 2). The increase in the rate of deposition of corrosion products on the zir- conium alloy in 9300 h of testing (in comparison with the rate of deposition in 2600 h) is explained by an increased concentration of iron in the system during the testing pe- riod (up to ?2 mg/kg). Irradiation in the reactor spectrum with intensity 1012-1013 neutrons/cm2? sec in the absence of a thermal flux practically does not intensify the rate of deposition of corrosion products on a zirconium alloy possessing a dense black oxide film (Table 3, alloy 1). Irradiation in- creases the rate of deposition of corrosion products on the zirconium alloy only in the case when the color of the film formed on the alloy changes from black to a lighter color, and, consequently, its density changes (see Table 3, alloys 3 and 4). As is evidenced by the literature data, the rate of deposition of corrosion products on the jackets of fuel cells, made of zircalloy, is somewhat higher under conditions of irradiation (Table 4) than the results obtained on samples in the absence of a thermal flux (see Table 3). Regardless of the du- ration of the testing, despite the fact that the concentration of corrosion products in the coolant in experi- ments with fuel cells was significantly lower (0.006-0.04 mg/kg, see Table 4), in comparison with the iron concentration in the system (0.05-0.1 mg/kg, see Table 3), the rate of deposition on the fuel cells proved higher than on samples without a thermal flux. As is evidenced by the results of Table 4, as well as [7], the rate of deposition of corrosion products on the zirconium alloy depends on the values of the thermal flux (the authors do not characterize the oxide film formed on the jackets). In [8] it was indicated that although ionizing irradiation somewhat increases the rate of deposition, it is a function of the amount of dissolved and colloidal iron in the system. In the opinion of the authors of this work, the influence of irradiation on the rate of deposition of corrosion products of iron on zirconium alloys must be related to the oxide films formed on the alloy itself. Thus, thin dense oxide films can adsorb substantially less iron oxides and other corrosion products than thick loose and more porous oxide films. If this assumption is correct, then the amount of deposited iron should depend on the color of the oxide film and its thickness, i.e., ultimately on the weight gain. Data on the dependence of the rate of deposition on the color of the film on alloy 1 under conditions of irradiation with a thermal neutron flux with intensity 3.0 ?1013 neutrons/cm' ? sec (t = 280?C, time of testing 3450 h), are presented below: Rate of deposition ? 10-3, Color of film g/m2. day Black Dark gray Light gray 14 1.04 2.16 3.48 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 5. Dependence of the Rate of Depo- As is evidenced by the data cited, the rate of depo- sition on the Weight Gain of Samples with sition depends on the color of the film (the lighter the film, Oxide Films of the Same Color and, consequently, the looser it is, the higher the rate of Color of film Alloy No Rate of . deposition Weight 10-4 g/m2 gain, mg ? day /cm2 Black (obtained with ir- 3 1,39 8 radiation) 1,39 30 2,78 20 1,39 17 2,08 95 2,78 12 2,78 17 2.78 24 4,86 11 4,86 13 Dark gray (obtained with irradiation) 3 1 2 7,65 7,8 165 176 9 21,6 53 Light gray (obtained with 27,8 610 irradiation) 12,5 530 deposition of corrosion products). Under conditions of irradiation on samples of a zirconium alloy possessing black, dark gray, and gray films, the amounts of deposits increase correspondingly. Thus, the amount of deposits on the surface is a function of the properties of the oxide films formed on zirconium alloys. Under conditions of irradiation without a thermal flux, when, as a rule, a lighter oxide film is formed on the samples, there is two to six times as much deposition as without irradiation. A change in the weight gain that is not accompanied by a change in the color of the film does not lead to any significant change in the value of the deposition (Table 5). It may be assumed that the deposition of corrosion products on the surface of construction materials is of an electro- chemical nature. The rate of deposition should depend on the potential of the zirconium alloy and the presence of contact of the alloy with other materials. However, experiments conducted in an electrochem- ical autoclave on an alloy of zirconium with 2.5% niobium and on an alloy of titanium at the temperature 300?C did not confirm this hypothesis. A sample of a zirconium or titanium alloy with area 50 cm2, to which a definite potential, maintained potentiostatically for 100 h, was communicated, was placed in an electrochemical autoclave. In the range of potentials from ?4 to +4 V (normal hydrogen electrode), the rate of deposition of cor- rosion products of steel varied lathe range 0.005-0.02 g/m2. day (Fig. 2). The observable fluctuations, as can be seen from Fig. 2, are not a function of the potential communicated to the electrode, but are explained by a difference in the concentrations of the corrosion products in the medium (0.02-0.15 mg/kg). Thus, on a titanium alloy in the potential interval from ?4 to +4 V (normal hydrogen electrode)* and a stress in water at the temperature 300?C, a uniform dark phase film is formed. An analogous dependence is observed on the zirconium alloy in the potential interval from ?1 to +1.9 V (i.e., in the case of formation of a dark oxide film on the surface, corresponding to the passive region of the anodic polarization curve), but then, as the potential is increased to +2 to 2.5 V, a white oxide film is formed (corresponding to the region of superpassivation of the anodic polarization curve), and the rate of deposition of corrosion products at the potentials in this region increases significantly (curve 1, Fig. 2). Probably the increased rate of deposition of corrosion products on the zirconium alloy in this case should be explained by a change in the sorption properties of the film formed on the surface of the alloy, and not by the value of the set potential. The process of deposition of corrosion products on the surface of construction materials is not of an electrochemical nature. Thus, evidently the rate of deposition of corrosion products (iron oxides) on zirconium alloys is a function chiefly of three components: the iron concentration in the coolant, the thermal flux, and the prop- erties of the films formed on the alloy. Thus, the dependence of the rate of deposition of corrosion prod- ucts of iron on an alloy of zirconium with 2.5% niobium on the concentration of corrosion products in the medium found in this work convincingly shows that the iron concentration in the water of operating nuclear installations, from the standpoint of the formation of possible deposits on the surface of construction ma- terials, should be less than 0.5 mg/kg. The results obtained permit us to assume that the deposits of corrosion products should be negligible when the water system is observed. The authors of [9], who investigated the deposition on fuel cells, ar- rived at an analogous conclusion. *A potential of ?4 V was communicated to one of the samples in the autoclave, and a potential of +4V to the other. 15 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Thus, the rate of deposition of corrosion products of iron on zirconium alloys under static and dy- namic conditions in water at 300?C, including conditions of irradiation, was evaluated. On the basis of the aforementioned we can draw the following conclusions. 1. If the zirconium alloy is corrosion-resistant and a uniform black oxide film is formed on its sur- face, then: 1) with increasing iron concentration in the system (more than 0.5 mg/kg) the rate of deposition of corrosion products of iron on the alloy increases significantly; 2) the rate of deposition of corrosion products of iron on zirconium alloys decreases with time and when the pH is raised from 7 to 10; 3) increasing the oxygen concentration in the medium and irradiation in the reactor spectrum with in- tensity up to 103 neutrons/cm' ? sec practically does not increase the rate of deposition of corrosion products of iron on a zirconium alloy in the absence of a thermal flux; 4) the rate of deposition of corrosion products of iron on the zirconium alloys does not depend on the potential in the passive region. 2. The rate of deposition of corrosion products of iron depends substantially on the quality of the ox- ide film formed on the zirconium alloy. Thus, the rate of deposition of corrosion products on samples with a dense black oxide film is lower than on samples possessing a lose light colored oxide film. LITERATURE CITED 1. A. I. Gromova et al., Teploenergetika, No. 6, 54 (1970). 2. H. Hami et al., NSI-Tr-61 (1966). 3. W. Pearl, M. Fitzsimmons, and M. Siegler, Trans. Amer. Nucl. Soc., 4, No. 2, 349 (1961). 4. J. Wanklyn and P. Fones, J. Nucl. Mater., 6, No. 3, 291 (1962). 5. I. K. Morozova et al., Teploenergetika, No.-10, 72 (1970). 6. Garigliano Nuclear Power Plant Operation Report for 2nd Quarter of 1967 (TID-24131). 7. A. B. Andreeva et al., in: Transactions of the Symposium of the Council of Economic Mutual Aid, "State and prospects of the development of atomic electric power plants with water-moderated water- cooled reactors" (Moscow, 1968) [in Russian], Vol. 2, IAE, Moscow (1968), p. 357. 8. J. Simon et al., WAPD-CDA(AD)-446 (1959). 9. L. Joseph, Nucleonics, 24, No. 3, 51 (1966). 16 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 MECHANISM OF REDUCTION OF URANIUM HEXAFLUORIDE BY HYDROGEN Yu. N. Tumanov and N. P. Galkin UDC 546.6:541.121 The reduction of uranium hexafluoride by hydrogen is usually represented [1-5] by the equation of the exothermic reaction (UF6)gm+(112)gas(UF4), 2(I-IFlgas- 69.8 kcal. (1) Although the thermodynamic characteristics of this reaction indicate that the thermodynamics do not limit the reduction of uranium hexafluoride by hydrogen [6], in practice this process begins only at 498- 523?K, and is slow and incomplete even at 873?K [7]. The difficulty of reducing 1SF6 by hydrogen is usually attributed [1-7] to the high activation energy; to reduce this, one usually employs atomic hydrogen, generated by a gas-plasma reactionrof hydrogen with fluorine, by an electric discharge [8], or by dissociation of ammonia [1]. The experimental activation energy of reaction (1) is 8.15 kcal/mole [5]. Since the activation energies of the elementary stages may differ markedly from that of the overall reaction, the relatively low activation energy of reaction (1) indicates a complex and stagewise re- duction mechanism and the presence of a limiting state. Our paper deals with these aspects. Reaction (1) may be represented to a first approxima- 48 tion as consisting of two stages: 0 0 r21 1,0 X 1 0,6 0,4 300 500 700 Temperature, ?K 900 Fig. 1. Degree of hydrogen reduction of UF6 versus absolute temperature: 1) cal- culated curve at a molar ratio 1SF6 : 112 = 1:1; 2) calculated curve at a molar ra- tio UF6: 112 = 1: 5; 3) experimental curve [2] at a molar ratio 1SF6: 112 = 1:5, con- tact time 30 min. (tiFe)gas-1- (II2)gas..= (UF4)gas ? 2(H.F) g as+ 7'4 * kcal, (2) (UF4)gas= (UF4)s ? 73.1 t kcal. Although the first stage (2) is endothermic, it is not limited by thermodynamics (Table 1). The high exoeffect of condensation of 1SF4 is responsible for the overall exothermic effect of reaction (1). The fact that when 1SF6 is reduced by hydrogen under fairly mild conditions both the tetrafluoride and pentafluoride are present, may be some indication$ of the stagewise reduc- tion mechanism of 1SF6, according to which reaction (2) takes place in two stages: (3) *We took the following value of the heats of formation of gas- eous fluorides at T =298?K and p =1 atm: AllijF6 = -510, 77 ? 0.45 kcal/mole [9], AHijF5=? 449 ? 5 kcal/mole [7, 10], AllijF4 =- 374.9 ? 5 kcal /mole [11, 12], AT-T --HF 64.2 ? 0.3 kcal/mole [13]. tThe heat of sublimation of UF4 was assessed from data of Akishin et al. [12]. $UF5 may be obtained by the reaction 1SF4 + 1SF6-' 2 UF6. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 21-25, January, 1972. Original article submitted January 6, 1971. 0 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 17 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 1. Results of Calculation of the Equilibrium of Reaction (2) Temperature, ?K 298 400 600 1000 1400 1800 2200 2000 Equilibrium constant Ke , atm 1,26.104 2,95.105 6,46.106 7,17.107 7,24.107 7,41.107 7,58.107 7,76.107 Degree of conversion nf TIF- 0,988 0,998 ? 1 ? 1 ? 1 ? 1 ?.? 1 ? 1 *.Thethermodynamic properiies of uranium fluorides are given in /14/. TABLE 2. Results of Calculation of the Equilibrium of Stagewise Reaction of Re- duction of UF6 by Hydrogen T, ?K Reaction (4) Reaction (5) !x ? degree Ke' atml of conver- sion of UF? Ix Ke' atmi ? degree of conver- ion of UF5 298 4.17.106 ? 1 3,02.10-3 0,05 400 1,26.06 ? 1 2.:14? 10-1 0,345 500 5,80?105 ? ? 1 3,98.100 0,745 600 3, 82.105 ? 1 1,95.101 0,893 1000 9,i2.l0 i 4,58.102 0,08 1400 6.46.104 ? 1 1,02.100 0,99 1800 2.89.104 ? 1 2.63.103 0,095 2200 2.0.104 ? 1 3.8.103 0,999 2600 3000 1,55.104 1,26.104 ? 1 ? 1 5.103 6,46.100 ? 1 ? 1 (UFO)gas+ .(H2)gas= (UF5)gas-j,- (11F)gas? 2.4 kcal (4) (UF5)gas+ (H2)gas = (UF4)gas+ (HF) g as+ 9.8 kcal (5) The reduction of UF6 to the pentafluoride is not limited by thermodynamics, but if we disregard conden- sation of UF4, reduction of the pentafluoride to the tetra- fluoride takes place quantitatively only above 1000?K (Table 2). Therefore if condensation of UF4 in the reac- tion zone is retarded in some way, we cannot assert that the equilibrium of the reduction of UF6 by hydrogen to UF4 is wholly displaced to the right. Although the assumption of stagewise reduction Of UF6 agrees qualitatively with the experimental data, Eqs. (4) and (5) do not reveal enough about the mechanism of (1). Furthermore, the experimental curve of the reduction of UF6 to UF4 versus temperature [6] lies far below the calculated data (Fig. 1), which is hardly possible under the conditions of continuous displacement of equilibrium of UF4 condensation. Since all practical methods of hydrogen reduction of UF6 involve the appearance of atomic hydrogen in some way or another, we mus, examine the ways in which hydrogen atoms are generated in the system UF6 ?H2. The role of atomic hydrogen is usually reduced [1-4] to evolution of the heat of recombination in the reaction zone by the reaction -= H2-104.2 kcal. However, markedly exothermic reactions of direct reduction of UF6 are just as possible: (lHogas-H (I-1)gas? (UF5)gas (11F)g2,s ? 54,5 kcal, (UF5)gas (H)gas=- (UF)gas -I- (HF) gas? 42,2 kcal. (6) (7) (8) How can hydrogen atoms be generated during reduction of UF6 in a reactor with a "hot wall"? Three schemes of hydrogen atom generation in the system UF6?H2 may be visualized. Scheme 1 ? via dissociation of H2 molecules: = 21-1 -[ 104.2 kcal. (9) Scheme 2? via dissociation of UF6 molecules: (Mgas= (UFs)gas -I- (F)gas-I 80.77 kcal , (F)gas-1- (H2) gas-- (IIF)gas; - (II)gas? 31.1 kcal (11) Scheme 3 ? via formation of monoradicals during bimolecular collision by the Semenov scheme [15]: (10) (U I"5 ? F)gas-:- (II H II) gas (UFs)gas+ (II ?)gas- (II)gas+ 49.67 kcal , (12) where UF5, fluorine, and hydrogen are monoraclicals. All the schemes include markedly endOthermic stages, but scheme 3 is thermodynamically more ad- vantageous than schemes (1) and (2) (Table 3). 18 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 3. Thermodynamic Characteristics of Reactions Leading to the Appearance of Hydrogen Atoms in the System UF6-H2 T, ?K Scheme Scheme Scheme K atm x-degree of K, dissociation of H2 Ke , atm to x-degree of dissociation Ke atm of IJFE? x-degree of conversion of Hz Ke atm x-degree of , , conversion 12 of UF6 298 5,92,10-72 1,22.10-36 ? 10-52 600 2,12-10-33 2,3.10-17 10-23 1000 5,1.10-18 1,13-10-9 3,02.10-" 1100 2,34.10-11 2,42-10-6 3,16.10-6 1800 1,27.10-7 1,78.10-4 1.855.10- 2200 3,14.10-5 2,8-10-3 1,01.101 2600 1,46.10-3 1,91.10-2 1,596 3000 2,47-10-2 7,83-10-2. 1.23-101 10-20 3,17.10-12 5,62-10-6 1,78.10-3 5.10-2 3,1-10-1 7.7.10-1 9,6.10-1 8,52.1m1 2,34.106 2,57.104 ? 2,09.103 4,28-102 1,37.102- 6,02.101 7,98.10-30 2,95-10-10 8,92.10-12 2,6.10-4 1,92.10-4 6,5.10-2 1,44..10-1 4,4.10-1 4.82.10 7,9-10'1 5.2.101 2,69-102 9,77.10-1 8,92.102 9,87.10-1 Therefore the following mechanism of reduction of UF6 by hydrogen may be presented F5 --- 1")gas (H--H)gas (UF5)gas 1,- - F)gas+ (H) gas , F6) gas+ (1I)gas -> (UF4) gas+ (1-1F) gas , (UF6)gas+ (H)gas (11F6) gas+ (HF) gas , 2(II)gas --> (IlOgas, (UF4) gas -? (UF4)0 Furthermore, a certain part is also played by the reactions: 1"4)gas-1- (UF6)gas = 2(UF6)gas - 12. 43 kcal, (13) (UF4) s (UF6)gas ii (-02F9)s (14) 3(liF4).s (UFO gas (1.14F17) s (15) etc. An attempt must be made to assess the kinetic constants of the elementary stages included in schemes 1-3. Let us first assess the rates of establishment of dissociation equilibria of UF6 and H2, because they are the limiting values in schemes 1 and 2. If we take as the rate the value 1/T (sec-1), where T is the time required for the partial pressures of hydrogen and fluorine to reach half the equilibrial values [1], then for bimolecular reaction (9), which must be written as at a pressure p 116 M iE 2H+ M, (16) 106 p? LTF6 = 0.5 atm, we get 2.23.1012 ?1 = I1PmkG Ke9P112 1,2 Ke 1/7 (17) To assess the value of 1/TF we must find the velocity constant of reaction (10). This was calculated from the two independent equations: -1 1 k 10 f exp - ?1Ein E Eo ? -1 k7' AS* kio exp R ) exp E,-RT R7' ' (18) (19) where X0 is the velocity constant of monomolecular decomposition of excited UF6 molecules; f is the number of oscillators involved in the reaction; E0 is the activation energy of the elementary stage; R, k, and h are respectively the gas constant, the Boltzmann constant, and the Planck constant; and AS* is the change in entropy. The results of calculations by Eqs. (18) and (19) agree closely (Fig. 2) if we put f = 3, AS* = S -UF5 -= SLTF6' E0 EUF5-F = 80.72 kcal [14], 19 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 6 4 2 -2 z 4 n 6 0 8 o 10 -18 0 0,2 44 0,6 0,8 40 1,2 1,4 Reciprocals of temperature /0 2/ 711( Fig. 2. Logarithm of velocity constant of the reaction UF6-.? UF5 + F versus the reciprocals of temperature. 0) 18; X) 19. 1,6 For the value of liTF we obtained the expression ? = 2k' (K. )112 10 eio ? (20) The results of the calculation (Table 4) show that dissociation equilibrium of UF6 is reached in the range 1800-600?K more rapidly than for H2 by a factor of 0.5-4. The velocity constant of reaction (11) in the range 1000-4000?K may be assessed by the equation [16] ?'7 76 .10"T? 2500-69exp RT ) . (21) Beginning at T 1800?K the role of dissociation of UF6 during its conversion to the tetrafluoride be- comes appreciable and, with a further increase in temperature, scheme 2 becomes predominant. However, at temperatures in the range 1000-1500?K, reduction of UF6 apparently Proceeds via scheme 3. The activation energy of reaction (12) may be assessed by the equation [15] Eact= EuFt, + En?H? EH? ; (22) it is 49.67 kcal. For reactions of saturated molecules of type (12), the preexponential factor is equal (with high probability) to the value 1013 cm3 ? mo1e-1 ? sec-1 [15], so that -1 -1 ki2 10,3 exp 49 600 ) 3. RT cm mole . sec (23) To calculate the velocity constants of reactions (7) and (8), we may propose the equation 0.28E ?F RT ? - -1 1 k7_8 10'3 exp ) cm3 mole (24) . sec An equation of this type was used for calculating the kinetic constants of the analogous reduction of sulfur hexafluoride: Calculations by the equations 20 4'6+ SF, ?HF. (25) k ( 30 000 4- 5000 ) ? ==- 2.10" exp , [16] RT 1c25= 1013 exp 27;7,00 ) Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 4. Rate of Establishment of Dissociation Equilibria of Hydro- gen and Uranium Hexafluoride T, ?K I-12 218 UF6 U F 6 F Ke atm -1 1/ r , sec K atm T F, sec -1 600 2;12.10-33 2,85.10-19 10-23 1,18.10-9 1000 5,1.10-19 5,04-10-3 3,02.10-11 1,43.10-1 1400 2,34.10-11 5,51.109 3,16.10-9 2,4.101 1800 1,27.10-7 2,54.102 1,855.10-3 4,0.102 give results displaying satisfactory mutual agreement. Therefore /c8= 10" exp ( 22600) cm3 ? mo1e-1 ? sec-1, (26) RT 26100 \ cm3 , k7 ,- 1013 exp ( mole-1 ? sec-1. (27) RT I The value of k6 for the reaction 2H +H2 '-'" 112 + 112 in the range 290-7000?K may be calculated by the equation [16] k6 = 6.03 .1018T-1. ? 9 cn.16' mole-2 ? sec-l? (28) In accordance with the Frenkel' equation [17], the rate of removal of supersaturation of uranium te- trafluoride by formation of nuclei of the condensed phase in UF4 vapor has the form: ?7,2.103o, T5/ (1g P/ 1.13- 10,o2p g* sec (29) T3 (1g uF4 exp ( m )1/2 i , pl:a 2 - where u' is the surface tension; p and pc? are respectively the vapor pressure and the equilibrium pressure; and g* and m are respectively the critical size of the nucleus and its mass. For the velocity constant of k13, by analogy with k7 and k8 we may write the equation 0.28Eup _F ki3 = 10" exp 2, 6 RT ) ? 10" exp ..00) cm3. mo1e-1 ? sec-1. (30) RT The role of reactions (14) and (15) cannot be determined, but it is apparently fairly great after the appearance of condensed uranium tetrafluoride in the system. The results may be summarized as follows. 1. Reduction of uranium hexafluoride by hydrogen to the tetrafluoride is an endothermic reaction; the exothermic effect of overall reaction (1) is due to condensation of UF4 and it cannot always be used for activation of UF6 reduction. 2. The appearance of hydrogen atoms in the system UF6-112 activates reduction not only by recom- bination of hydrogen molecules, but also as a result of markedly endothermic reduction of UF6 and UF5 molecules by atomic hydrogen. 3. Owing to the high thermodynamic stability of 112 and UF6 molecules, at least up to 1400?K, the primary stage of reduction of UF6 is the endothermic reaction of formation of monoradicals of hydrogen and UF5, accompanied by exothermic reduction of UF5 and UF6 by atomic hydrogen. 4. Above 1400?K an important part is played by dissociation of UF6 molecules, accompanied by the exothermic reaction of atomic fluorine with hydrogen molecules to form atomic hydrogen. 5. The concentration of UF4 molecules in the gas phase decreases continuously to the equilibrial con- centration owing to formation of nuclei of a condensed phase, which at a = 5 .103 erg ? cm-2 include from 4 to 67 UF4 molecules in the range 400-1200?K. Under these conditions the rate of condensation of UF4 is 104 sec-i. Condensation of UF4 molecules may be accompanied by decomposition of UF6 molecules, giving two UF5 molecules. 6. The appearance of condensed tetrafluoride in the system UF6-112 may accelerate decomposition of UF6 with formation of UF5 and "intermediate" uranium fluorides. 21 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 7. The experimental activation energy of hydrogen reduction of UF6, 8.15 kcal/mole, is not the true activation energy. The activation energy of the limiting stage of reduction of UF6 is ??? 49.67kcal/mole. The appearance of condensed uranium pentafluoride, atomic hydrogen, and condensed tetrafluoride reduces the activation energy of reduction of the hexafluoride. LITERATURE CITED 1. C. Harrington and A. Ruele, Technology of Uranium Manufacture [Russian translation], Gosatomiz- dat, Moscow (1961), p. 108. 2. Chemistry and Technology of Uranium Fluorides (N. P. Galkin, editor) [in Russian], Atomizdat, Moscow (1961), p. 226. 3. Ya. M. Sterlin, Metallurgy of Uranium [in Russian], Gosatomizdat, Moscow (1962), p. 402. 4. Technology of Uranium (N. P. Galkin and B. N. Sudarikov, editors) [in Russian], Atomizdat, Mos- cow (1964), p. 327. 5. N. B. Sudarikov and E. G. Rakov, Processes and Equipment of Uranium Manufacture [in Russian], Mashinostroenie, Moscow (1969), p. 164. 6. J. Dawson, D. Ingram, and L. Bireumshaio, J. Chem. Soc., 1421 (1950). 7. J. Katz and E. Rabinovich, Chemistry of Uranium, Vol. 1 [Russian translation], IL, Moscow (1954), p. 355. 8. W. Sham, R. Spenceley, and F. Feetzel, US Patent cl. 23-14.5, N 2, 898, 187 (1959). 9. J. Settle, H. Feder, and W. Hubbard, J. Phys. Chem., 67, 1892 (1963). 10. A. Wolf, J. Posey, and K. Rapp, Inorg. Chem., 4, 751 (1965). 11. Yu. V. Gagarinskii and L. A. Khripin, Uranium 'ITetrafluoride [in Russian], Atomizdat, Moscow (1966), p. 90. 12. P. A. Akishin and Yu. S. Khodeev, Zh. Fiz. Khim., 35, 1169 (1961). 13. Thermodynamic Properties of Individual Substances (V. P. Glushko, editor) [in Russian], Izd-vo AN SSSR, Moscow (1962). 14. N. P. Galkin, Yu. N. Tumanov, and Yu. P. Butylkin, Thermodynamic Properties of Inorganic Fluo- rides [in Russian], Atomizdat, Moscow (1972). 15. V. N. Kondrat'ev, Kinetics of Chemical Gaseous Reactions [in Russian], Izd-vo AN SSSR, Moscow (1958). 16. V. N. Kondrat'ev, Velocity Constants of Gas-Phase Reactions [hi Russian], Nauka, Moscow (1970). 17. Ya. I. Frenkel', Selected Works, Vol. 3 [in Russian], Izd-vo AN SSSR, Moscow- Leningrad (1959). 22 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 CALCULATION OF REGULAR SYSTEMS OF NEUTRON ABSORBERS Ya. V. Shevelev and I. L. Chikhladze UDC 621.039.51 The most frequently used method of calculating systems of absorbers is based on a solution of the criticality equations [1-3]. It is not easy to calculate the effect of absorbers by this method, however, since the neutron distribution must be investigated simultaneously both over the reactor as a whole and close to each individual absorber. The difficulties are increased if several energy groups are taken into account. We propose a two or three stage procedure for calculating systems of absorbers occupying a small fraction of the reactor volume. First the actual reactor is replaced by an equivalent reactor in which the neutron distribution over the region occupied by the absorbers is a smooth function of coordinates, possibly having discontinuities in magnitude and slope at some boundary. At large distances from this region the neutron distribution coincides with the true distribution. The equivalent reactor is critical when the actual reactor is critical. The criticality condition for the equivalent reactor and the smooth neutron distribution in it are then found. If necessary the true neutron distribution over the region occupied by the absorbers is calculated. The calculation as a whole is greatly simplified, and the last stage is not always necessary. Statement of the Problem. Let us consider the simplest problem of this class. Suppose a plane strip of material which is a weak neutron absorber contains cylindrical rods which absorb thermal neutrons only (an unessential restriction). The strip is placed in the reactor core or reflector and is periodic in the y direction (Fig. 1). A cell contains n rods positioned arbitrarily at the points ri, where i = 1, 2.....n: the rods are numbered in order of increasing xi. The coordinates of the remaining rods are given by r,?,= rr+ ma, where m = ?o0. ..., ?1, 0, 1, ... 00. (1) It is assumed that pi/L xn; a y) dy, x < xi. 0 The true flux 43 outside the absorbers is given by (2) (3) where q is the density of thermal neutron sources. We assume the strip is so thin that q is the same on its lower and upper surfaces. For .:13T (x) we obtain the equation d.r2 (4) Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 27-32, January, 1972. Original article submitted February 16, 1971. 0 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 23 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 ---4-----. Fig. 1. Cell with n rods spaced with pitch a The problem can be solved by assuming that q varies or that the properties of the media and the source strengths inside the strip and on opposite sides of it are different, but we limit ourselves to the simplest case when D D_; g q_-= q+; L+=- L_. At large distances from the strip clo coincides either with 434. (above) or with (13_ (for x < 0). We extrapolate the functions cl3+ and c13_ by Eq. (4) inside the strip to some ar- bitrary boundary separating the regions, e.g., to the line x = 0. We obtain the values of the functions &Ho and 4._o and their derivatives dc13.4_0/dx and d(1)_0/dx on this boundary; the values of 040 and 01)_0 may differ, and the values of the derivatives will also differ. The specific prop- erties of the strip must appear in a definite relation among the four quantities mentioned and also possibly q/Z which appears in Eq. (3). Since the equations are linear and Eq. (3) is second order, these relations can be written in the form m(+1)0+0 Ap2),I10_0 ,r?na N iv ?4- dcpdx+? (1)a d&0+ K'> -f--- = dx m(42)0+0+ jp2)0_0 Na da'd;to N(2>a +.K12) =0. By using Eqs. (4) and (5) the solution of Eq. (3) in the lower part can be related to the solution above the strip. Thus the dimensionless coefficients M2, A2, and K1,2 completely determine those properties of the strip which affect the thermal neutron flux far from it. In solving the criticality problem these equa- tions are used instead of the standard joining equations for thermal neutrons. In a similar way equations of the type of (5) are obtained for neutrons undergoing moderation. After the criticality condition has been found it is possible to return to the equations determining the actual rather than the smoothed out fluxes, and to construct them. (5) We determine the coefficients M, N, and K. Solution of the Problem for Constant Neutron Flux at the Surface of the Absorber. The problem is simpler to solve when the absorbers are rather widely separated (pi/a ?1). We write the solution of Eq. (3) as the sum of a regular part cbreg and singular solutions symmetric with respect to each rod 71 00 c1:0 (r) CD reg(x) + E ci E K, (1 r -1"11 1=1 ? co The function (1) r e g(x) satisfies Eq. (3) over the whole volume. The singular terms satisfy Eq. (3)with- out the right hand side. Since Eq. (3) does not hold close to the surface of an absorber, effective boundary conditions are set [4]: (6) where acl) =0(11V+Pii) ; yi 7 (Pj Irr?ril=pi By substituting (6) into (7) we obtain the equation for the coefficients Civi+ civt; + oreg(x.,)+ 4 1C, -0, k [ 2 K0 ( I ?ri?ma ) ? v ri ? a ) a ' L a ' 771=--- co v (Lpi) (.2.L ' ? JI.) pi L L, a L ? The term 7L/A in Eqs. (8) and (9) is separated out because, as is shown in the Appendix, if a/L 0 the quantities remain finite. The coefficients v1 are calculated in the Appendix. By using (8) the Ci can be expressed in terms of cbreg which by Eq. (3) is given by 24 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 (7) (8) Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Fig. 2. Smoothed out extrapola- ted neutron flux for vi < 0; absor- bers are placed in the plane of sym- metry. The shaded region is "dis- placed." It is known [5], that and therefore where reg o (x) = 4)rego ch Tx + L d d.c reg o sh ' Lx " (1 cliL-r-) ' l' L ' (11) where ''reg o and d4'reg0/dx are the values of this function and its derivative on the arbitrary boundary x = 0. Thus the values of the Ci are expressed linearly in terms of q/Z and the two so far un- determined constants (I, reg o and dl)reg okbc. Let us calculate the functions (I)?(x). We first average the sum in (6) E Ko 1r ) 4 E Ko .0 ?,=_00 0 ix+ ? ri ?Oa .,a) 1) . 4 ? L After the change of variable m + = t we obtain E? ( ) dt =L , ?Or\ 2 \ L2 1 dt. 711--,-0. ? la ? K0 (Irp2+ q2) dq = 1 00 22?X, C K0 (11.?ri?Za?a11)dE =" e L 0 1a=-00 Thus according to (3) and (13) GDT = (Dreg 60,, -so+ E ci e L ; = E aL e a (12) (13) (14) (15) Each of the functions oI satisfies Eq. (14) without the right hand side and (Dreg satisfies it withzthe right hand side. Therefore the extrapolations of the functions dIT are obvious. (I)-0 ? ' ? (1) E ciexi/L' +0 ? (nreg o xa E Ce; 77. , N-1 - /L da)-0 d(1) rego , xa -x-/L (1)..0= (Drego -i - L Cie ; dx = dx a L ? We rewrite Eq. (8) by using (11): cid)reg0 x q Xi CiVi E , E Oregoch L sh (1 ? Tr-) =0. (16) (17) The unknowns C-, -rego, and drego/th can be eliminated from (16) and (17) to yield two equations in (40, dt. (Aix, and q/Z since the number of equations in these systems is n + 4 and the number of unknowns elim- inated is n + 2. Therefore Eqs. (16) and (17) lead to relations of the type of (5), i.e., to explicit expres- sions for the required coefficients. Specific Types of Lattices and Analysis of Results. Arbitrary regular lattices can be analyzed by using Eqs. (16) and (17) and formulas (A.6), (A.7), and (A.10). In the simples case when n = 1 it is con- venient to set the arbitrary boundary along the line of centers of the absorbers. Then according to (16) and from (17) (D+o 0-0 --- (=Dreg o tL C,; do+o d(I)reg o dx dx C, d(Dreg o do+, (18) dx dx + (Dreg o = 0. (19) ' 25 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 1. Types of Absorber Lattices Considered and Results of Two-Group Calculations of Reflector Savings. The Core and Reflector Parameters Correspond to the IGR Reactor [6] Lattice structure ?,0 ,' d ----0,i4 .L1,' ft It v * 23,4 27,0 29.0 20,3 21,9 23,7 17,1 17,7 18.9 Vi Y2 T3 i S-/ 1 VA I 1.-- 17,0 20,5 22,3 15,7 10,8 18,0 13,8 14,2 14,9 -, .1 T2 ri Y 15,0 17,1 18,7 13,3 14,1 15,0 11,9 12,9 13,9 Yi 72 T3 13,3 14,9 16,1 12,4 1.3,0 13,i; t 11,4 11,6 12,6 10 T2 l'3 ? . .T . ? 41114. el X " 72 =1.3; y3 = 1.616 corresponds to IGR rods. In all three cases a= 14 mm. t Data for lattice used in IGR. By eliminating the unknowns Ci,reg?, an and dcDrego/dx from (18) d (19) we obtain the two equations 'D (I)+o = (D-o ; a dcb+0 , CLia dx at By comparing (20) and (5) we find /1/(:" - /1/(1); Ar(l)_]r(i)K(i)0. 2V(2)-- Ar(2); /1;14)-- a 2174!")* vi ? (20) m(2) Ar); K(2) _ 0. Equations (20) are similar to the boundary conditions which describe absorption in a thin foil [4]. Thus an array of cylinders can be regarded as equivalent to an absorbing layer for which the product of the thick- ness A and the macroscopic absorption cross section Ec is (A/c)equ- ''p phi a a 3vla 3 ; 1. 2,t 2ap (21) However the analogy with a thin absorber does not completely represent the situation. The quantity v1 can be negative for a/(2p) < ir as is confirmed by more accurate calculations. If a zero value of vi in Eq. (20) can be interpreted as the blackness of the equivalent absorbing layer becoming infinite* then a negative value of vi can only be interpreted as the result of the displacement of the medium by absorbers of finite thickness (Fig. 2). It is clear that the width of the displacement region must not exceed the diam- eter of the cylinders. Fortunately this physical requirement is satisfied even in the crude approximation considered. By using Eqs. (16) and (17) in the two-group approximation and taking the usual continuity conditions at boundaries for neutrons undergoing moderation, reflector savings were calculated for various lattices of absorbers placed close to the core in the reflector of the IGR reactor [6]. The results of the calculations are shown in Table 1 and in the corresponding graphs of Figs. 3 and 4. These calculations permitted the selection of a five-rod absorber lattice for the lower reflector of the IGR reactor. The calculated results are in satisfactory agreement with experiment. *Actually it is well known that the flux cl) is not zero even on the boundary of an absolutely black absorber. 26 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 6, mm 28 ? 2 7 ? 25 ? 25 ? 24 ? 23- 22 ? 21 ? 20- 19 ? 18 ? 17 ? 16 15 14 13 ? 12- 11 10 ? 20; 0,9843 I I 1 1 i 1 2 3 If 5 n 6, mm 28 ? 27 ? 26 ? 25 ? 24- 23- 22- 21 ? 20 ? 19 ? 18 ? 17 ? f6 ? 15 ? 14- 13 ? 12 11 10 10 15 20 25 d, mm Fig. 3 Fig. 4 Fig. 3. Reflector savings 6 as a function of the number of absorbing rods n in a cell for rods of various diameters and various values of 7. Fig. 4. Reflector savings 6 as a function of the diameter of an absorbing rod dfor various numbers of adsorbing rods n in a cell and various values of y. Values of are listed in Table 1. APPENDIX Calculation of coefficients v1vj, and v. According to (9) (ri ?.r; a ? L) ; a ( a )= [ K0 ( Vx2 (j/, mar' Following [4] the Poisson summation formula is used: y (27(m) E '111=-0c v .= co CO Using (A.2) and (A.1) we obtain ar, a (A.1) (p (K) e-ivk dK. (A .2) ( I \ x y +) 1 N Z?I C x2_4_ y_4221 2 ( 27t 2n 1 Making the change of variable t = (y + ak/27r)/L and using the formula [5] p2+, Ko(Vp2+t2)= e " 0 we obtain where dk. 21t -i_STVt-t2 X2 oo e"* _du e u 4?udt, ? 00 Li , L2 ?i2av ?L t--t2 ?s2?i2xtv ?L us ?4n2v- ? u 2 1,/ e ds = 2 V Tut e at ? ?oo ?co (A.3) (A.4) Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 27 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Thus .0 v e2nu .0 :EL iv E a .c e a2 4/.20 du a a a or iv2a 2- (1+4112,4 L-i2) -x-1 00 a L al, L e r 41 j2 a a i L'2 2 17 r-c 1 e 2 dt , 1+ 40,,2 b a2 V=---00 and further 00 L q i2.7tv IL- _If' -,1 Ili?(23-tv -1=-)2 ?a -7 P = 7;.- E? a v=-00 V1H-(2av --.a ) - e Separating out the term with v = 0 we obtain 2vixi -V1+ ? ivo:t1J- 03c-:-y ; a) ,..= 21L (e---E-Isi , Re e a 1 1) i V a ( 9fr,vL') Equation (A.6) is the working formula and has the obvious limit as a/I, 0: 2 2:tvL) Ix ? V (X")= 7('iax I ' Re Yi ie 2a' ? -a = ni? ax11 ? a COS 2a =1- a v e-2:r! a (e-2.1-1s1 sh a 2)2j= 1 2ax , In 12 (ch ?a ?CoS ?2ay . a As v increases the terms of series (A.6) converge rapidly to the corresponding terms of the series (A.7). In view of this the obvious relation (A.5) (A.6) (A.7) V r-rz V L.= co +.(5. v S v k=00), (A .8) can be used where the Sp are the partial sums of the corresponding series. In particular it follows from (A.7) that if lix2 + y2 = p, then for p>kT, the flux of monochromatic neutrons has a sharp maximum, and its extent is determined by the time of retarda- tion to the specified energy. For neutrons with E kT, the thermal motion constitutes the factor prevent- ing the achievement of the maximum possible flux value, since a considerable proportion of the neutrons are scattered into a higher energy range, with the acquisition of energy. Furthermore, the length of the pulse is very considerable in this case, being mainly determined by the lifetime of the neutrons in the equi- librium spectrum. The intensive cooling of the moderator to a temperature at which the condition kT (nod)cr. TABLE 1. The der Values (in centimeters) s=1 s=2, 8=3 X =- X, 0,60 0,75 0,85 X -= Xi 0,25 0,30 0,35 x=0 0,17 0,17 I 0.,17 The a's lose energy primarily due to "cooling" in collisions with electrons. Here the a range depends on the electron density n and temperature T: T3/2 = a ?n , (5) where we are to set a = 3.8 ? 1010 cm4/degil- 2. At an electron density of n = 4 ? 1022 cm-3 and temperature of T = 108?K, the a range is /a = 0.95 cm. We will assume that the shell has an infinite heat capacity, so we can assume zero temperature on the surface bounding the plasma. At the center of the plasma layer symmetry requires that gradients vanish. Accordingly, the boundary conditions on Eq. (1) can be written (6) Converting to the dimensionless variables = xd-1, 0 = TA-1 and assuming a power-law temperature dependence for the thermal conductivity, 34 = PTk, we can convert Eq. (1) with boundary conditions (6) to a Oh = ts--10 40 +1 q (no d, 0); (7) 0 It= = 0. (8) Examination of the structure of Eqs. (1)-(3) shows that the right side of Eq. (7) will depend on the electron density and the plasma dimensions only through the combination n0d: (k +1) (nod)2 q IF (no d) F qT1 Ak+1 (q p' = Fn-2 QT = T11-2)1 (9) where qF and qT are functions of the dimensionless temperature 0; n0 = /IA 0 is the plasma density at the center of the layer; and d is the half-width of the layer. This problem is apparently quite similar to the familiar problem of a "thermal explosion" in chemical kinetics. In fact, there are significant differences, due to nonlinear thermal conductivity (4), which differs from the Arrhenius conductivity by heat-evolution law (2) and the existence of volume energy loss due to radiation. As a result of the combined effects of these factors, a thermal explosion in its usual sense [2] does not occur during thermonuclear combustion. The steady-state temperature distribution satisfying Eq. (7) and boundary conditions (8) must be of the form 0 0 (a? nod), i.e., it must depend on nod as a parameter. There are no other parameters in this ?problem. In order for there to be a steady-state solution, certain conditions must be satisfied. These conditions must take the form of some dependence of the parameter nod on the temperature 00 = = 0: nod -= (01) ? 40 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 (10) Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 nod ?10-22cm-2 10 9 8 7 5 4 3 ? 2 1,0 9 2 8 7 65 6 7 8 9 108 10 9 8 7 5 10 ;9 8 7 6 nod ?10-a.cm 2 3 4 5 6 7 8 9109 a T?1( 3 4 5 6 7 8 9109 TV( dno 10-2 C111-2 10 9 8 7 5 5 4 2 1,0 .9 8 7 65 6 7 8 9108 2 3 4 55 7 8 9 109 r/K Fig. 2. Temperature dependence of nod found under the assumption of spa- tial homogeneity for the heat sources. a) s = 1; b) 2; c) 3. It is shown below that the function f(00) reaches a minimum at some temperature 0,, corresponding to the minimum possible value (nod)er; with nod < (nod)er a steady state is not possible. The dimensions der calculated for the normal density of solid deuterium turn out to be comparable to the a range. We will accordingly consider two limiting cases. 1. In the first case of d 108?K. 1) s = 1; 2) 3. R 2s 71. qx P k+1 (n0)2 ? The quantity Qx = ntiqx represents the rate of heat loss per unit volume due to conduction. This loss depends on the exponent k in the expression for x as well as on the configuration of the plasma volume (s). Figure 1 shows a typical ob = (1)(00) dependence for a fixed nod value. The intersections of the 43(00) curve with the line cl) = 1 correspond to steady states; if the curve maximum lies below the line, no steady state is possible. With nod > (nod)er there are two possible states of thermal equilibrium. Here the equilibrium corre- sponding to the left-hand intersection is unstable. In fact, because of the positive derivative of the function (1)(00), which represents the ratio of the volume heat evolution to energy loss from the plasma, the slightest overheating of the plasma will result in self-heating. As a result the system should enter a new equilibrium state, corresponding to the right-hand intersection. The characteristic transition time is FQ Tr "-? nT (15) At a plasma density of n = 4 ? 1022 cm-3 and a temperature of T = 108?K, this time is T f/ 5 ? 10-9 sec. By way of comparison, we note that the total "burn-up" time of the mixture under these conditions is TF-10-8 sec. A thermal equilibrium cannot be reached with nod < (nd)er, and the plasma quickly cools. The corre- sponding cooling time* is TX ? d2 nix ?-? 10-8 sec with d 1 cm. According to the theory for a thermal explosion [2] with d < der, on the other hand, a steady state is reached, and with d> der the temperature of the reacting mixture increases without limit (a thermal ex- plosion). This discrepancy arises because in the thermal-explosion problem the corresponding function 4,(00), if plotted on the basis of the Semenov diagram, would have a minimum at some point Omin (in con- trast with the case under consideration here). Figure 2 shows temperature dependences of nod found under the assumption of a spatially homogenous heat source qk. The function F is assumed given by F = 1?e (16) We consider three different cases corresponding to the different curve labels in Fig. 2: 1) the heat is transferred by electrons, and we have 'A, = xe; 2) heat is transferred by ions (the electrons are mag- netized), and we have x = xi; 3) the thermal conductivity if formally set equal to zero (there is no thermal *Here and below, all the calculations correspond to the normal density of -solid deuterium, with n = 4 ? 1022 cm-3 and T = 108?K. 42 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 contact between the plasma and walls), and we have x = 0. Here the second case corresponds to the ap- plication of a magnetic field of 3 ? 105 G < B < 2 -106 G. The third case should be treated as purely hypo- thetical. 2. In the other limiting case of large plasma dimensions (la d), the heat evolution can be assumed local and dependent on the local temperature. The corresponding problem is solved numerically; Fig. 3 shows temperature dependences obtained for nod. In the transition region (d /a) the results of the numerical calculations are in satisfactory agreement with results of the preceding model and with the results of [3], obtained by reducing to the problem to the thermal-explosion model [2]. Figure 4 shows characteristic temperature distributions which arise in the stable plasma state. The temperature is seen to change relatively slowly over most of the gap and to fall off rapidlyto zero as 1. At a low-temperature thermal equilibrium we observe oscillations in the temperature distribution. These oscillations are damped as the average plasma temperature is raised. The oscillations are expressed most clearly in the spherical and cylindrical cases. The oscillations arise because in this temperature range the heat-source function may change sign. Table 1 shows der values for the normal density of solid deuterium: n = 4 .1022 cm-3. With 14. = xi and x = 0, we can assume der Fy the main source of information on Ey is the measurement of radiative capture, as was shown in [7]. When necessary a cor- rection was introduced for the capture of neutrons after scattering. Table 1 shows that the radiative widths are nearly the same for neutron energies up to 1200 eV. The mean value fy = 24 MeV and the deviations from the mean barely exceed the experimental error which is about 10% for most resonances. An increase in the accuracy of the measurements might possibly show 46 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 1. Parameters of U238 Neutron Resonances EQ, eV rrt, MeV ry, MeV Eo, eV rn. MeV rIP MeV 611t0,1 24+1,5 25?2 621?0,9 33+10 24+3 80,7j0,1 2,2 +0,2 629+0,9 7+1 102,4+0,1 70j3 26?2 662+1 150+20 22+2 1169?0.1 22?3 23?2 694+1 40+10 24+2 145,8+0,1 0,84+0,06 709+1 20+5 26+3 165,4+0,1 3?0,3 733+1,1 3,5+0,6 189,5+0,2 164+5 22?2 767+1,2 7+1 208,4+0,2 481-2 26+3 792+1,2 6+1 237,6_0,2 27?3 26+3 822+1,3 66+16 24+3 273.9+0.25 ? . 22?3 25+3 853+1,4 26+3 291,2+0,25 16,4?2 23+2 857+1,4 25+3 311,7?0,3 0,9+0,1 869+1,4 5+2 ? 348.1+0,35 78+10 22+2 907+1,5 40+10 25+3 377+0,4 0,9+0,15 939+1,6 120+20 24?3 398,1?0,45 4.7?0,5 960+1,6 130+20 22?3 410,7?0,45 20?3 25?4 994+1,7 27+3 434,6+0,5 8?1 1 026+2 8+2 464,1+0,55 5+0,5 1 057+2 90+30 22+3 479,4+0,6 3,5+0,5 1100?2 25+3 519+0,7 42?6 23+2 1142?2 26?3 536,2+0,7 55+15 23+2 1 170+2 23+3 580,7+0,8 36+6 23+2 1179?2 22+3 594,8+0,8 93+10 24+2 1197?2 26+4 small fluctuations in I', but in any case Fig. 1 shows that the fluctuations reported in [4] are clearly not real. The mean value = 19 MeV obtained in [4] is also a considerable underestimate. We previously reported the main results on the radiative widths of U238 [8], and the data of the Belgian group [9] published at the same time are in good agreement with ours. In conclusion the authors thank T. S. Afanas'evoi and N. T. Khot'ko for help in performing the mea- surements. LITERATURE CITED 1. L. Bollinger et al., Phys. Rev., 105, 661 (1957). 2. F. Firk, J. Lynn, and M. Moxon, Nucl. Phys., 41, 614 (1963). 3. J. Garg et al., Phys. Rev., 134, B985 (1964). 4. N. Glass et al., Proc. II Conf. on Neutron Cross Sections and Technology (D. Goldman, editor) (1968), p. 573. 5. J. Rosen, Phys. Rev., 118, 687 (1960). 6. M. Asghar, C. Chaffey, and M. Moxon, Nucl. Phys., 85, 305 (1966). 7. Kh. Maletski et al., Yadernaya Fizika, 9, 1119 (1969).- 8. Kh. Maletski et al., Soviet? French Seminar on Nuclear Data [in Russian], Dubna (1970). 9. G. Rohr, H. Weigmann, and J. Winter, Proc. II Intern. Conf. on Nucl. Data for Reactors, Vol. 1, CN 26/18, IAEA, Vienna (1970). 47 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 ABSTRACTS VARIATIONAL COMPOSITE METHODS OF CALCULATING NEUTRON DISTRIBUTION IN NUCLEAR REACTORS I. S. Slesarev, A. M. Sirotkin, UDC 621.039.5/6 and V. V. Khromov The variational approach has broad possibilities for the creation of composite methods which, in cal- culations of physical systems, allow the simultaneous use of approximations of different orders within the scope of one method or the application of several different methods at once in an arbitrary combination of their approximations. The variational formulation of the problem usually consists of the construction of a functional for which the equation under examination is a Euler? Lagrange equation. A one-velocity kinetic equation in plane-parallel geometry was used in the study, and the functional Fo, stationary for the solutions of the initial equation and equal to the quantity keff, was examined. The fact that Fo allows the use of discontinuous trial functions is significant. A sufficiently general approximate representation of the desired solution in the geometry examined is N(z) 'jk(x, tt) E (ti) a;th (x), (1) n=-0 where ik is the number of the phase space region for the variables x and /2; Qni is some known polynomial; ik an is the desired function; N is the number of members in the series, which depends on the number i of the physical zone. Many approximation methods may be obtained through the variational method, if trial functions are used which are a particular case of (1) and satisfy the restriction that Fo be stationary. It is shown that the functional examined is suitable for the derivation of the equations for DPn, Sn and of other methods. Since Fo allows the use of all kinds of trial functions, having the form of (1) in different zones of the reactor or of another physical system, all "matching" conditions for equations for a broad class of approx- imation methods are obtained from a single principle ? the need for the functional Fo to be stationary. The extraction of matching conditions at the boundaries of zones where the change of method or num- ber of approximations takes place is the important step in the derivation of the composite methods equations. Matching conditions of a general type, which are suitable for combinations of many existing methods, were formulated in the study. Equations and matching conditions of certain variational composite methods ? DPn-DPrn, DPn-Srn, Sn-Sm (the indices n and m indicate the possibility of using different approximations in neighboring zones of the system) ? were presented as concrete examples. The DPn-DPrn method was verified in calculated investigations of the quantity keff and of the neutron distribution in a multiregion heterogeneous multiplying system. The results of the calculations, which are presented, demonstrate the flexibility of the method and its high degree of accuracy, together with a sig- nificant decrease in the extent of the computations. This decrease is due to the reduction in the order of the approximations for the DPn method in those zones where this is warranted a priori from physical con- siderations. Translated from Atomnaya Pnergiya, Vol. 32, No. 1, p. 53, January, 1972. Original article sub- mitted September 22, 1970. 0 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 48 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 RADIOACTIVITY OF METAMICT ZIRCONS I. M. Lipova and G. A. Kuznetsova UDC 553.494:539.16 Interpretation of the nature of the metamict state in minerals is one of the urgent problems in current mineralogy. The most popular relevant viewpoint on metamict minerals sees them as primary crystalline substances coverted to an amorphous form under the influence of radioactive radiations emitted by uranium and thorium incorporated in the minerals. Zircon is a most abundent accessory mineral, and an important industrial source of zirconium, and is known in nature in both crystalline and metamict states. The role played by radioactive radiation in met- amict decay of a mineral was studied in tests run on a series of zircon specimens (incorporating zircon per se, cyrtolite, malacon, alvite, naegite, etc., comprising a continuous series from crystalline to complete x-ray amorphous differences). The way the uranium and thorium contents, the a-activity, the total a-ex- posure dose vary, the forms of occurrence of uranium and thorium, and the distribution of uranium and thorium in the minerals, were studied. Specimens of zircons from various types of geological formations existing in the USSR and in foreign countries were investigated. The entire series of zircons was arbitrarily broken down into three groups on the basis of the number of reflections on the Debye powder diagrams: crystalline, semimetamict, and metamict. The uranium content was determined by the luminescent method, and the thorium content was deter- mined colorimetrically, using arsenazo-III reagent. The a-activity was measured in a thin layer of the specimen applied to the substrate, with a scintillation counter and a PS-10,000 scaler used in the measure- ments. The total a-exposure dose was calculated by multiplication of the a-activity by the absolute age of the mineral. The uranium content and thorium content in the zircons increase from the crystalline differences (hun- dreds of a percent of uranium and thorium) to metamict differences (whole percents of uranium and thorium). But no exact quantitative relationship linking the degree of x-ray amorphousness of zircon and the content of the radioactive elements (uranium and thorium separately, or their sum) was observed. The thorium/uranium ratio is determined by the genesis of the rocks. As a rule, Th/U > 1 in zircons from pegmatites of alkaline granites, alkaline syenites, nephelin syenites, greisens, albitites bound with alkaline rocks, and hydrothermalites of alkaline composition, and usually the ratio Th/U < 1 in zircons from granites, granitic pegmatites, and apogranites. The degree of x-ray amorphousness of zircon tends to increase with increasing total dose of uranium and thorium a-emission: in the case of crystalline zircons n 10" a/mg, in the case of semimetamict zir- cons n 10" a/mg, and metamict zircons n 1016-17 a/mg. Uranium and thorium are represented as both by the scattered or dispersed form and by microinclu- sions of radioactive minerals. The latter are syngenetic in rare instances, but more often epigenetic with respect to the zircon. When the content of inclusions of uranium and thorium minerals is high, the direct relationship between the degree of x-ray amorphousness and the a-radiation dose breaks down. Dispersed uranium is unevenly distributed throughout the volume of the mineral (microradiography). Portions with a higher density of a-tracks correspond to the optically isotropic phase, and portions having a lower track density correspond to the anisotropic phase of the mineral. These data are confirmed by the microprobe method. The maximum uranium content in the specimens investigated was detected in Japanese naegite (6.66% U308 in the transparent fraction of the mineral containing no microinclusions when viewed in 497-fold mag- nification). All of the uranium seems to be included isomorphically in the structure of ZrSiO4 (4'mole % uranium). Naegite is the most deeply metamict of the whole series of zircons investigated. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 53-54, January, 1972. Original article submitted March 23, 1971. 49 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 MONTE CARLO CALCULATIONS OF CHARACTERISTICS OF SECONDARY ELECTRONS KNOCKED OUT FROM VARIOUS MATERIALS BY 1, RADIATION*- V. V. Smirnov and A. V. Malyshenkov UDC 539.124.17 Energy spectra, angular distributions, and quantum yields of secondary electrons knocked out by )'- radiation from aluminum and copper targets of different thicknesses were calculated by the Monte Carlo method. In the region of energies of interest (0.4 to 1.3 MeV), production of electrons in the irradiated material was due solely to Compton scattering and to photoelectric absorption of the Y-emission. Values of the energies and directions of escape of the Compton electrons were calculated on the basis of the Klein ?Nishima formula. The pattern of angular distributions of the photoelectrons was obtained on the basis of tabular data compiled by Hallberg. The target-depth distribution of the electrons formed was assumed uni- form. In dealing with the motion of an electron through the material, the entire path traversed by the elec- tron from the point of origin to the target boundary was broken up into discrete segments within which the electron energy losses were determined according to Bethe?Bloch theory, and the angular distributions were estimated in conformity with Mollier theory. As a result of these calculations, the energy spectra, angular distributions, and quantum yields of secondary electrons knocked out by the 7-radiation of the radioisotope isotopes of Co?, Cs137, and Auln from aluminum targets 0.1 Ro and 0.6 R0 in thickness were determined (R0 is the total range of the electron having the highest energy). The quantum yields of the secondary electrons knocked out of an aluminum tar- get of equilibrium thickness (0.6 Ro) by y-radiation emitted by Cog), Cs137, and Aulm, in the forward direc- tion (0-90?), was, respectively, 8.0, 3.0, and 1.1 in units of 10-3 electron photon, and respectively 0.25, 0.20, and 0.06 in the same units in the backward direction (90-180?). Comparison of the calculated energy spectra, angular distributions, and quantum yields of secondary electrons knocked out in the forward direc- tion and available experimental data indicated agreement within 10%. The calculations of quantum yields of secondary electrons for targets of various thicknesses (alumi- num and copper targets) indicated that the relative yield of electrons for a given thickness expressed in terms of a fraction of Ro, and the atomic number of the target, is independent of the energy of the incident '7-photons. The relative yields of secondary electrons in the case of aluminum and copper targets of dif- ferent thicknesses were approximated by empirical formulas which were in agreement with the experimen- tal data to within 5%. THE KAON FACTORY ? A TWO-STAGE (^J 3.7 GeV) ISOCHRONOUS CYCLOTRONt L. A. Sarkisyan UDC 621.384.633.5 Many research centers are carrying out investigations into the creation of "kaon factories," that is, accelerators aimed at producing 3-7 GeV protons with an average beam current of the order of 100 ?A. Tables 1 and 2 indicate possible parameters for three versions of a cascade-type isochronous cyclotron pro- posed by the author in 1970 [1, 2]. *Translated from Atomnaya Energiya, Vol. 32, No. 1, p. 54, January, 1972. Original article sub- mitted June 23, 1971. tTranslated from Atomnaya Energiya, Vo . 32, No. 1, pp. 55-56, January, 1972. Original article submitted May 3, 1971; revision submitted August 2, 1971. 50 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 1. Parameters of 2.7 GeV Three-Stage Cyclotron System Stages of cyclotron Ho , Oe N 71, cm (4 roc, CM r?. Cm r, C111 F? w K' eV, MeV Aystemp GeV /rev" First 6000 8 8 0,2 --- 1 -,--,c.: Q r -.,.:,: 2 521 .-. 0 415 0,281 0.8 1 Second 3000 12 14,1 ' 0,65 --- 1,86 < Or - 0.1 X0 the slope of the curve for as a function of the electron energy increases with increasing Z. 4. The width tends to increase with a lowering of the threshold for recording bremsstrahlung. With an increase in the angle the difference in the angular distributions measured by detectors with different thresholds becomes more noticeable as predicted theoretically by Hisdal [4]. The dependence of the width of the angular distributions on electron energy, thickness, and atomic number of the target in the range of target thicknesses and energies examined can be described by the semi- empirical expression _b(z) 200+ a (E , Z)e t deg, 84 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 (1) Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 where 0 = 57.28 m0c2/E; m0c2 = 0..511 MeV; E is the electron energy in MeV; t is the target thickness in radiation lengths; and a (E, Z) and b(Z) are functions of the electron energy and the atomic number of the target material. The functions a (E, Z) and b(Z), determined from the experimental data, have the form: a (E., Z) = (5.17 ?1,32 Ig E+ 2.28?10-2Z) a (E, Z) = (4.72 ? 1.826 lg E+ 7.62.10-2Z) b (Z)= (5.1-10-3+ 3.1?10-4Z). The widths of the angular distributions of bremsstrahlung calculated by Eq. (1) do not differ from the ex- perimental values by more than 10%. A comparison of the experimental angular distributions of bremsstrahlung with theory confirms the conclusion of Lanzl and Hanson [5] that the use of the Moliere formula [6] for the angular distribution of electrons gives better agreement with experiment than does the Schiffer and Lawson [3, 7] theory in which the Williams [8] and Rossi and Griesen [9] formulas are used for the angular distributions of electrons. The calculations were compared with measurements made with a copper detector. The Lanzl and Hanson calculations give good agreement with experiment for small angles (0 50) and target thicknesses less than 0.1 Xo. for the Cu 63 detector: for the ionization chamber; LITERATURE CITED 1. H. Koch and J. Motz, Rev. Mod. Phys., 31, 4(1959). 2. V. P. Kovalev et al., Atomnaya Energiya731, 289 (1971). 3. J. Lawson, Proc. Phys. Soc., A63, 653 (1950). 4. E. Hisdal, Phys. Rev., 105, 1821 (1957). 5. L. Lanzl and A. Hanson, Phys. Rev., 83, 959 (1951). ? 6. G. Moliere, Z. Naturforsch., 3a, 78 (1948). 7. L. Schiff, Phys. Rev., 83, 252 (1951); E. Muirhead et al., Proc. Phys. Soc., A65, 59 (1952). 8. J. Williams, Phys. Rev., 58, 292 (1940). 9. B. Rossi and K. Griesen, Rev. Mod. Phys., 13, 240 (1941). Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 MATCHING OF ACCELERATING CHANNELS IN A HIGH ENERGY PROTON LINEAR ACCELERATOR B. I. Bondarev and L. Yu. Solov'ev UDC 621.384.64 To achieve particle energies of the order of 100-200 MeV in a linear proton accelerator, a transition is made to an accelerating field of shorter wavelength. With a wavelength reduction by a factor n, the phase width of a bunch becomes n times larger, as measured in the phase scale of the shortwave section, while the phase capture area of the shortwave section remains the same as the capture areas of the longwave sec- tion. At the same time, the momentum width of a bunch remains practically unchanged during the transition into the second section; it is less than the momentum capture area. Therefore the phase width of a bunch can be decreased at the entrance to the shortwave section by virtue of an increase in the momentum spread of the particles. Known devices for matching accelerating channels* require the introduction of a third, intermediate wave. The construction of such devices requires rf oscillators, accelerating systems, and other equip- ment operating at the intermediate wavelength. The two matching devices described below operate at the wavelength of the first, longwave section of an accelerator. The first of the devices is a cavity installed between the two sections of the accelerator and operating at the frequency of the longwave section. The frequency of the longitudinal oscillations in this cavity is greater than the frequency of the longitudinal oscillations in the other cavities of the longwave section of the accelerator. The cavity length is equal to an odd number of quarter wavelengths of the longitudinal os- cillations. Increases in the frequency of longitudinal oscillations in the matching cavity is achieved by an increase in synchronous phase (to 60-70?) and amplitude of the rf field (to maximum permissible values). This cavity also accelerates particles but with lower efficiency. The operating principle of the matching device is shown in Fig. 1. We consider the phase plane (0, h), where 0 = (p? (pc, h= (p ? pc)/pc, Q and p are Longwave section 'Shortwave section Matching cavity the phase momenta of the accelerated particles, and (pc and Pc are the phase and momentum of the center of the bunch. We assume that the particle coordinates in this plane at the entrance to the matching cavity of the long-wave section lie within the shaded ellipse A. In proportion to the accel- eration in the matching cavity, the particle image points in the phase plane are shifted into an ellipse which is more elongated along the ordinate when compared with the ellipse which is the envelope of the bunch because of the higher frequency of longitudinal oscillations in the cavity. After a quarter cycle of the longitudinal oscillations, i.e., at the exit of the last cavity of the longwave section, the bunch will have the shape of the shaded ellipse B. The phase Fig. 1. Matching accelerating channels with *A. D. Vlasov, Theory of Linear Acceleration [in Russian], a quarter-wave cavity. Atomizdat, Moscow (1965), p. 75. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 79-81, January, 1972. Original article submitted December 18, 1970. 86 0 /972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 IShortwave section Longwave section Drift Ldr Matching cavity Resonator L res 27r P? PC / PCc Fig. 2. Matching of accelerator channels by using a drift space and matching cavity. dimension of the bunch is reduced and the momentum spread increased while the area of the image ellipse is preserved. Such an ellipse better fits in the capture area of the shortwave section. Optimum matching can be achieved by choosing the synchrotron phase and amplitude of the accelerating field in the matching cavity. The second device consists of a drift space and matching cavity at the end of the longwave section. The wavelength, synchronous phase, and field intensity in the matching cavity are chosen to be the same as in the other cavities of the longwave section, and the cavity length is selected such that the longitudinal dimension of a bunch at the exit from this section of the accelerator is minimal. Consider the operation of such a matching device. Let St be the frequency of the longitudinal oscilla- tions at the exit of the next to last cavity and in the last, matching cavity of the longwave section (we neglect adiabatic variation of parameters in it). As before, we assume the particle coordinates in the (0, h) plane at the e5cit of the next to last cavity lie within the ellipse A (Fig. 2), which satisfies the equation 11)2 h2 = (D2 H2 (1) with (13 and H the semiaxes of the ellipse A, which are related by the expression H = (STY2/co)(13, where co is the frequency of the accelerating rf field; Y = (1? P2)-1/2; g = v/e; v is the particle velocity; and c is the velocity of light. After passing through a drift space of length Ldr, the particle representative points are displaced parallel to the abscissa by an amount ?lch, where k = 2rLdrAY2 and X is the wavelength of the accelerating field. The ellipse A transforms into the ellipse B, the equation for which is (11)? hh)2 h2 (D2 -1- H2 ? (2) After drifting, the particles arrive at the matching cavity and the ellipse B is rotated by an angle 7112 + a in proportion to the acceleration in the cavity, and is transformed into the ellipse C, the axes of which coincide with the coordinate axes. The matrix M which describes the transformation of coordinates at the cavity entrance into the coordinates at the exit is M-=+- c21,2 ) . (3) ( Qyz ? sin a, cos cz ? cos a, ? sin a (0 Subjecting the coordinates 1/) and h in Eq. (2) to the transformation (3), we obtain an equation for the ellipse C at the exit of the longwave section. To make the axes of the ellipse C coincide with the coordinate axes, we set the coefficient of the Oh term equal to zero in the equation for this ellipse. Then 1 2 arctg , Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 (4) 87 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 where m = (S2Y2/co)k. Substituting the resultant value of a in the equation for the ellipse C, we find that its phase spread is reduced by a factor x in comparison with ellipse A: (5) and the momentum spread of the particles is increased by the same factor. By selecting Ldr, the shape of the ellipse can be optimally matched to the capture area of the short- wave section. It is easy to show that nonlinearity and nonconservation of longitudinal motion, as well as random per- turbations of it, do not reduce the practical efficiency of the matching devices discussed. In principle, the matching devices discussed above can be used where there is a need for linear trans- formation of bunch phase space. In high-energy and high-current linear proton accelerators (meson factories, neutron generators), matching devices can be used for matching the accelerating channels of the longwave and shortwave sections of the accelerator, making it possible to prevent particle loss and to increase operational reliability and acceleration efficiency. In linear accelerators used as injectors for proton synchrotrons, matching of ac- celerating channels helps to decrease particle momentum spread at the accelerator exit along with an in- crease in acceleration efficiency. 88 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 EFFECT OF NONLINEAR RESONANCES ON BEAM DIMENSIONS IN THE 70-GeV ACCELERATOR V. I. Gridasov, K. P. Myznikov, 'UDC 621.384.6 and V. N. Chepegin The emittance of an accelerated proton beam is one of the most important parameters determining the operating efficiency of an accelerator extraction system. However, the very first measurements made at the IHEP (Institute of High-Energy Physics) showed that beam emittance at the end of acceleration dif- fered considerably from the calculated value [1]. Our present purpose is the clarification of the reasons for this effect and an experimental study of the possibilities for suppressing it. The dependence of horizontal and vertical dimensions of the beam on the magnitude of the magnetic field in the accelerator is shown in Fig. 1. In this case, acceleration was produced at the central radius beginning at 4000 Oe. The beam dimensions were determined by means of internal targets. A target was introduced into the beam at a given time in the acceleration cycle. Its position could be changed both ,mm r,z 25 20 15 10 5 4000 6000 8000 Fig. 1 --? 10000 H2Oe 97 ?916 9, N-, 30, =29 2 / / / / / __411. V - 41%0TIDANN OPP N? yrAllrfill .c .414 I a* N/ / Fig. 2 2 6 Fig. 1. Dependence of horizontal (1) and vertical (2) beam dimensions in a ra- dially focusing section on the magnetic field in the accelerator during accelera- tion at the central radius. ----) The same dependence when a correction was introduced into the magnetic field gradient in the accelerator. Fig. 2. Operating region for the frequencies Qr, z with linear resonances to fourth order. 1-6) Operating point trajectories for radial beam displacement at various inductions; 1) 4000, 2) 9000, 3) 10,000, 4) 11,000, 5) 11,500, 6) 12,000; aa, bb, cc) operating point trajectories corresponding to acceleration at radii equalling ?10, ?5, and 0 mm; AB) operating point trajectory with gradient correction. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 81-82, January, 1972. Original article submitted January 6, 1971; revision submitted May 10, 1971. C 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 89 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Or,z ,nun 25 20 15 10 -20 -15 -10 -5 0 5 10 15 20 00 500 1000 E ,keV Fig. 2. Dependence of the quantity a for PU235 on neutron energy: co) FEL 1970, ,pres- ent study; V) LASL, 1962, [1]; 0) ORNL, 1967, [3]; V) IAE , 1956, [5]; ) FEI, 1958, [6]; x) FEI, 1965, [7]; --O--) UCRL, 1970, [9]; --0--) OIY,aI, 1970, [14]; --0--)ORNL ?RPI, 1970, [11]; --N---) Harw, 1970, [12]; OIYaI? FEL 1970, [13]. Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 [4] with coatings of U235 and PU239. In experiments with plutonium this quantity for our detector was Cpu239 = 0.2955 ? 0.0073, and in experiments with uranium, Cu235 = 0.2962 0.0053. Moreover, to control the conditions of the experiment the quantity C was periodically determined in the process of the experiment through the detection of spontaneous Pu240 and Cf252 fission events. During the analysis of the experimental results for high neutron energies a small correction for the dependence of the probability C on the average number of fission neutrons v was introduced. The values of the quantity a obtained in the experiment for U235 and PU239 are presented in Figs. 1 and 2. They are the result of averaging live independent series of measurements for U235 and nine for PU239. The error indicated in the figures is root-mean-square error obtained as a result of averaging and does not include the indeterminancy of the constants of the experimental apparatus Elf/eye and C, characterizing thereby the indeterminancy in the relative energy dependence of the quantity a. The total absolute error of the quantity a, including the indeterminancy of all quantities in (1), is 10-15%. The majority of experi- mental data available at present on the quantity a in the region of neutron energies 10 keV-1 MeV is also presented in the figures. It is possible to note a substantial agreement of all experimental data on PU239 obtained on van deGraaf accelerators by the analagous method. For U235 our data in the region of neutron energies 20-100 keV lies systematically lower by 15% than the results of [1-3]. However, it must be observed that in these studies significantly thicker (^. 6 times) samples were used, and a detailed comparison evidently requires consid- eration of the different effects of resonance blocking. The marked structure in the dependence of the quan- tity a on the neutron energy obtained by us both for U235 and for PU239 is worthy of attention. This structure may be the cause of significant discrepancies in the case of U235 in the results of measurements of a by the transmission method in the spherical geometry on photoneutron sources Sb-Be [5-7]. The presence of such a structure in the quantity a is not surprising and may be linked with the strong structure in the fission cross section, which for U235 in this region of neutron energies was recently discovered [8]. In conclusion the authors express their gratitude to A. I. Leipunskii, L. N. Usachev, A. I. Abramov, and V. A. Romanov for their constant attention and cooperation in the completion of the present study and also to V. S. Shorin, M. V. Bokhovko, N. S. Kosulin, V. I. Volodin, and V. N. Kanaki for their participa- tion in the preparation and conducting of the experiments. LITERATURE CITED 1. J. Hopkins and B. Diven, Nucl. Sci. Eng., 12, 169 (1962). 2. L. Weston, G. de Saussure, and R. Gwin, Nucl. Sci, Eng., 20, 80 (1964). 3. G. de Saussure et al., Nucl. Data Reactors, Vol. II, Vienna, --IAEA (1967), p. 233. 4. V. N. Kononov et al., Pribory i Tekh. Eksperim., No. 6, 51 (1969). 5. P. E. Spivak et al., At. Energ., No. 3, 21 (1956). 6. V. N. Andreev, At. Energ., 4, 185 (1958). 7. A. A. Van'kov and Yu. Ya. SFavisskii, At. Energ., 19, 41 (1965). 8. B. Patrick et al., AERE-R 6350 (1970). 9. Y. Czirr and J. Lindsey, Nucl. Data Reactors, Vol. I, Vienna, IAEA (1970), p. 331. 10. Van-Shi-Di et al., Phys. Chem. Fission, Vol. I, Vienna, IAEA (1965), p. 287. 11. R. Gwin et al., Nucl. Sci. Eng., 40, 306 (1970). 12. M. Schomberg et al., Nucl. Data Reactors, Vol. I, Vienna, IAEA (1970), p. 315. 13. V. N. Kononov et al., Preprint P-3-5112, D-ubna (1970). 14. Yu. V. Ryabov et al., Preprint P-3-5113, Dubna (1970). 97 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 CHILL-CASTING METHOD OF BITUMINIZING NATURAL SORBENTS FOR Ir192* Kh. Daiev, G. Delchev, G. Gradev, S. Simov, and V. Zhelyazkov UDC 546.93 The chill-casting method of bituminizing the isotopes Cs137, Ag110,204, sr90, and Ca45 retained on natural sorbents (zeolite with clinoptilolite and vermiculite) has been described in the literature [1-3]. This article reports a study of Ir192 sorption by several naturally occurring sorbents, and the fixing of those sor- bents in bitumen by a method which we developed. In contrast to the above elements, iridium ions in aqueous solutions tend to form various complexes [4, 5] which have the effect of complicating iridium sorption processes. Data are available on sorption of iridium only on synthetic resins [6], none being available on sorption of iridium on naturally occurring sor- bents. It seems that the complicated relationship between the different forms in which iridium occurs adds difficulties to sorption of iridium on a specific cation or anion exchange resin. On the other hand, the lit- erature contains descriptions [4, 7] of sparingly soluble iridium compounds with silver, mercury, lead, thallium, etc., of the type M3IrA6, where M stands for silver, mercury, lead, or thallium, and the IrA6 denotes complexes of iridium in which A stands for Cl-, OH-, NO, and so on. Sorbents of that type ex- hibit high sorption power with respect to silver, mercury, lead, and thallium. We therefore undertook an investigation of the iridium sorption conditions via precipitation reactions, i.e., we converted an appropri- ate sample of sorbent to the silver, mercury, lead, or thallium form suitable for precipitation reactions, and passed a solution of iridium through the bed of sorbent. For example, in the case of the silver form of the sorbent, a reaction of that type can be represented as follows: 3Ag4 ?? Ag,T)C1, . (from sorbent) (from solution) (on sorbent) Sorption of Ir192 on natural sorbents (zeolite and vermiculite) and bituminization of sorbents retaining the isotope in question were investigated. *This research was done at Vienna under IAEA contract. TABLE 1. Chemical Composition of Sorbents (%) Sorbent Co 0 bI c).? 0 E. CO Zeolite with cli- 65,90 noptilolite Vermicu- 41,92 lite 0,45 5,46 12,97 5,41 2,30 4,03 0,43 23,84 2,12 0,61 4,93 0,28 0,08 0,82 5,93 77,015, 70 60 50 40 30 20 10 - 1 2 3 4 5 6 7 8 9 10 11 pH Fig. 1. Dependence of sorption co- 1,34 efficient ti of Ir192 on pH: 1) zeolite; 2) vermiculite. Physics Institute of the Bulgarian Academy of Sciences, Sofia. Translated from Atomnaya Ener- giya, Vol. 32, No. 1, pp. 87-89, January, 1972. Original article submitted May 20, 1971. 98 C 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 TABLE 2. Results of Experiments on Sor- bents with Presorbed Cations Cation Zeolite with clino- ptilolite specific ac- tivity, pulses 2min,m1 *nitial olu- tion solu- tion passed through bed Vermiculite sorp- tion co- effi- cient, To pecific ac- vity, pulses initial solu- tion solu- passed through bed tion Silver Mercury Lead Thallium 2040 2040 2040 2040 202 135 235 032 90,1 93,4 88,5 49,4 2040 2040 2040 2040 118 33 299 857 TABLE 3. Specific Activity of Natural Wa- ters and of Waters Washing Bitumen Block Specific radioactivity, nCi/liter Water 1970 1971 analyzed sorp- tion Octo- ber No- vem- ber De- em- ber Jan- uary Feb- ru- ary March co- effi-Water washing cient, bitumen block with embedded It 192 0,045 0,044 0,012 0,013 0,025 0,020 0,018 0,017 0,028 0,021 0,170 0,170 94,2 98,4 Radioactive 85,3 58,0 fallout The chemical composition of the sorbents used in the naturally occurring state appear in Table 1; the grain size belongs to the class (-3.0; +0.3 mm). The initial solution containing the iridium in the form of ammonium chloroiridite (N114)3IrC16 has a specific activity of 2040 pulses/min?ml. A specified volume of a solution whose pH is controlled by buffers was passed through a sample of sorbent at a specified flowspeed. The specific activity of the initial solution and of the solution passed through the sorbent was measured, and the sorption coefficient of iridium was cal- culated. The results, plotted in Fig. 1, lay bare the compli- cated dependence of the iridium sorption on pH, and the pos- sibility of retaining as much as 50% (roughly) of the iridium on the sorbents referred to. In the experiments staged with sorbents that had first been converted to their silver, mercury, lead, or thallium 7 form, a solution of silver, mercury, lead, or thallium in ni- trate form was passed through the sample. After washing with distilled water till a negative reaction was obtained for the cor- responding ion, a solution containing iridium was passed through the sorbent. The results (Table 2) attest to the possibility of sorption of Ir132 by natural sorbents in amounts of 98-99%, upon prior sorption of silver, mercury, or lead. Bituminization of sorbents retaining Ir132 was carried out according to a procedure developed by the authors [1]. Stor- age-battern bitumen was used to make the bitumen bowl, which was cast in a special metal chill mold. Two layers of sorbent were laid down in the bowl (Fig. 2): a lower layer of vermiculite and a top layer of zeolite. A solution of silver nitrate was passed through the sorbents, and after washing with distilled water, a solution of Ir132 with total activity of 10-3 Ci was passed at a flowrate of 15 to 20 milmin. After that, the activity of the Ir132 solution did not differ from the activity of the naturally occurring sample due to radioactive fallout. The sorbents were washed with distilled water (silver and iridium were not detected in the wash wa- ter), and after drying in air the bowl was sealed with molten bitumen. The bitumen block with sorbent "loaded" with the radioactive isotope was left to stand in the open. Measurements were taken on a monthly basis to monitor the?radioactivity of the water (rain or snow) wash- ing the block, and the status of the surface of the block was observed visually.* The results, listed in Table 3, show that the eluted radioactivity is of the order of magnitude of the amount due to radioactive fall- out. Fig. 2. Layout of bitumen fixing unit: 1) bitumen bowl; 2) radioactive solu- tion of Ir132; 3) sorbent treated with silver nitrate; 4) fiber glass (glass wool); 5) metallic gauze; 6) support stand; 7) control valve; 8) discharge tube. *The method of retention and the results of monitoring observations checking on the state of the bituminous block and on the radioactivity of the collected atmospheric precipitation washing the block are described in detail in [1]. 99 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 The investigations of Ir192 on natural sorbents (zeolite with clinoptilolite and vermiculite) established the favorable effect of the presorbed cations: silver, mercury, or lead, on sorption of iridium through the formation of precipitated compounds on the sorbents. The sorbents retaining Ir192 were bituminized by the chill-casting method. The method proposed here expands the range of applications of the chill-casting method for processing low-level and medium-level liquid radioactive wastes. LITERATURE CITED 1. Kh. Daiev et al., in: Management of Low- and Intermediate-Level Radioactive Wastes, IAEA, Vienna (1970), p. 739. 2. Kh. Daiev et al., Izv. Inst. Fiziki s ANEB Bolgar. Akad. Nauk, 22 (1971). 3. Kh. Daiev et al., Izv. Inst. Fiziki s ANEB Bolgar. Akad. Nauk (in press). 4. A. Werner and 0. Vzies, Ann. Chemie, 364, 87 (1909). 5. F. Bimish, Analytical Chemistry of Noble Metals, Part 1 [in Russian], Mir, Moscow (1969). 6. 0. Samuel'son, Ion Exchange Separations in Analytical Chemistry [in Russian], Khimiya, Moscow (1966), p. 347. 7. M. Delepine, Comptes Rendus, 149, 1073 (1909). 100 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 INFORMATION ALL-UNION IZOTOP AGENCY SERVING THE NATIONAL ECONOMY EXHIBIT AT EXPOSITION OF ACHIEVEMENTS OF THE NATIONAL ECONOMY V. A. Dolinin A topical exhibit designated as "All-Union Izotop Agency Serving the National Economy" was inaugu- rated in September, 1971 at the Atomic Energy pavilion of the Exposition of Achievements of the National Economy. This is the first time that an exhibit of that type has been set up at the Exposition. It consti- tutes a sort of report on the ten years of activities of the WO Izotop agency. This agency, set up in 1961, has been called upon to serve various branches of industry, agriculture, science, and medicine in providing them with sources of ionizing radiations, radioactive and stable isotopes, labeled compounds and rare earths, radioisotope process monitoring instrumentation, radiation techniques and equipment, personnel shielding equipment, equipment for handling radioactive materials, electron physics equipment, dosimetric and radiometric equipment. The problems highlighted by various sections of the exhibit are timely ones. The displays clearly indicate how the problem of utilizing nuclear and radiation processes in science and in industrial practice, posed in the resolutions of the XXIV Congress of the Communist Party of the Soviet Union, is being met. There are seven sections in the exhibit. The introductory section is devoted to the activities of the WO Izotop agency and of its subdivisions. The beautifully conceived display stands graphically illustrate the increased volume of WO Izotop deliveries in 1970 over the 1965 level, in percentages: Isotope production 200 Radioisotope process monitoring devices 180 Electron physics, dosimetric, and radiometric equipment 350 Shielding and personnel protection 250 Radiation equipment 150 Total volume of deliveries 278 Volume of export deliveries 676 It is also clear that the production of isotope equipment in 1970 increased by 318 items over the 1965 level, while the production of electron physics equipment, and of dosimetric and radiometric equipment, was increased by 175 items. The "Personnel protection and equipment for handling radioactive materials" division of the exhibit informs visitors of measures taken in the USSR to ensure labor safety in work with radioactive materials. Specimens of special plastic laminate protective clothing, as well as equipment for handling radioactive materials, such as: various types of glove boxes, hoods and dry boxes, remote-control manipulating equip- ment, protective devices, and conveying equipment, are on display in that section. Several types of gamma-ray nondestructive testing instruments were on display in the "Radiation equipment" section. At the present time, gamma-ray inspection and nondestructive testing is one of the Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 91-93, January, 1972. 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 101 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Fig. 1. In the exhibit halls. Fig. 2. In the exhibit halls. efficient methods available in quality control of materials, parts, and equipment (with no need to destroy or dismantle the equipment inspected), laying the basis for great strides forward in improving the charac- teristics of goods manufactured, improving the reliability of machine parts performance, and preventing damage to equipment, mechanisms, and parts. Visitors have the opportunity to become familiarized with the RID-11, 111D-21, Gazprom, andother gamma-ray nondestructive testing instruments, as well as acces- sories for gamma-ray nondestructive testing instruments. The radiation processing outfits designed for radiation research and radiation processes in biology, medicine, chemistry, and agriculture, were presented at the exhibit in the form of diagrams, photographs, and working mockups. The neutron activation analysis section deals with one of the most sensitive and up-to-date methods of ultimate analysis of the composition of materials, and displays a full-size K-1 neutron activation analysis set for oxygen determinations and a diagram of the SO-1 neutron activation analysis system. The "Radioisotope process monitoring instrumentation" section is the most representative one at the exhibit. Automated measurements of forgings and automatic control of 2000-ton and 3000-ton hydraulic drop forge presses with the aid of the RTP2-1S dual-channel radioisotope relay instrument have been in- stituted at the V. I. Lenin Neva Machinery Factory, with improved forging precision, increases in the 102 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 number of press strokes, better forging quality, and better working conditions resulting. Annual savings of 59,000 rubles are reported. Nine UR-8 radiosotope level gauges and 32 gamma relay units are in use at the Slavgorod chemical plant, for monitoring flowrate and fill level of liquefied gases and corrosive fluids. Savings of 200,000 rubles annually are reported. The installation of three radioisotope liquid density gauges at the Nikopol'marganets trust ore pro- cessing mill in Grushevka has resulted in annual savings of 60,000 rubles. Use of an ITShch-496 radioisotope thickness gauge on a coil cut-up line at the Novolipetsk metallur- gical plant, with automatic sorting and grading of steel plate, made it possible to free 30 workers for other assignments, and resulted in annual savings of 42,500 rubles. The RRV-64 radioisotope gauges and weight controllers for paper and cardboard sheet, installed on four machines at the Sloka paper and pulp combine, have constituted an efficient means of raising labor productivity, achieving savings in raw materials and finished materials, and in improving product quality. Savings resulting from the installation of RRV-64 devices on production lines have totalled 30-40 thousand rubles per year per device. The use of 120 radioisotope instruments on automatic process lines for interlocking in the event of cutting tool breakage has yielded savings of 500 rubles annually per instrument, through curtailment of scrap and turnover of tools. The display stand of the Karaganda metallurgical plant, showing 172 radioisotope instruments in ef- fective service for automated monitoring and control of the fill level of materials in tanks, for measuring moisture content and weight of sinter burdens, ash content of coals, thicknesses of hot-rolled plate, and analysis of raw materials and finished products, is of great interest. The use of 82 gamma relay units in the sintering department of that plant, for automatic monitoring of the fill level of materials in hoppers, has yielded 90,000 rubles yearly in savings. The display of the Krasnoe Sormovo plant gave an account of automatic control of metals casting on a continuous steel casting machine. Savings have amounted to 160,000 rubles a year. The "Electronic nuclear physics equipment" section presented full-size specimens of various types of equipment, including: PP-9-2M, BP-100, and PP-15 scaling circuits, the Protoka proportional-flow 47r-counter, and many others. Dosimetric and radiometric instrumentation for monitoring the radiation environment and ensuring radiation safety of personnel in handling of radioactive materials is on display: a pocket set of direct-in- dicating DK-02 dosimeters with the ZD-5 charging device, the KID-20 set of personnel dosimeters, the IFK-2, 3 set of personnel film badges, the IZV-1 portable dosimeter for monitoring the dust load in the local air and the content of radon daughters in dust, the 01'kha-1 aerosol radiometer, and the Araks dosi- metering device. The "Stable and radioactive isotopes" section is set up in an interesting and attractive way, informing visitors that the V/O Isotop agency is the general delivery agent for all isotope products in the USSR. Many of the display stands present accounts of the applications of stable isotopes in chemistry. biol- ogy, biochemistry, physics, and also applications of radioactive isotopes as labeled atoms in scientific and industrial research, as sources of ionizing radiations in automatic process control and monitoring instru- mentation. The exhibit came to constitute a large educational forum for hundreds of specialists in the national economy. Seminars were held for the benefit of specialists from various regions of the country on special passes issued by the Exposition of Achievements of the National Economy of the USSR. to promote more widespread utilization of the atom for peaceful purposes. 103 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 SEMINARS AND CONFERENCES AT V/O IZOTOP While the topical exhibit "All-Union Izotop agency in the service of the national economy" was being held at the "Atomic Energy" pavilion of the Exposition of Achievements of the National Economy of the USSR, the All-Union Izotop agency was holding five seminars. The agenda of these seminars consisted of presen- tation of reports on the agency's activities. The seminar participants were familiarized with the list of devices, dosimetric and electron physics equipment, supplied to industry by the agency for research and industrial use, and the new types of instruments planned for delivery in 1972. The seminars attracted a total of 250-odd specialists: representatives of ministries, representatives of management boards, scien- tific-research and planning institutes, grass-roots level isotope laboratories, organizations and industrial plants in the various cities and districts of the country. The seminars will contribute to more widespread acceptance and utilization of radioisotope techniques and equipment in the various branches of industry, agriculture, and in scientific and medical institutions throughout the nation. The three day seminar on the topic "Isotopes and isotope instruments in the national economy" was held at the Scientific-Research Institute for Nuclear Physics, Electronics, and Automatic Control attached to the S. M. Kirov Tomsk Polytechnic Institute, in July, 1971. About 300 engineering and technical per- sonnel from plants, scientific-research personnel, and party leaders took part in this seminar. An "Isotopes in the service of humanity" exhibit was running concurrently with the seminar. This exhibit displayed 250 items in isotope products, nuclear instrumentation, and personnel protection. The seminar and the exhibit stimulated a good deal of interest on the part of specialists in the city and nearby localities. A conference on "Radiation techniques in the automation of mines and ore processing plants" was held at Donetsk on September 22-24, 1971. Specialists from power and machinery management bodies of mining and ore combines dealing with automation, mine automation mechanics, and technology, and other special- ists, were attracted to the conference. The implementation and perspective applications of radioisotope equipment in the coal industry were discussed at the conference. The conference participants heard reports on experience in the introduction of radioisotope equipment and practice at the Donetskugol', Artemugol', Makeevugol', Voroshilovgradugol', and Pavlogradugol' combines. After hearing and discussing the papers and reports, the conference participants pointed out that a lot of work has been done in recent years on applications of radioisotope equipment at plants and enterprises in the coal industry. The conference participants were afforded the opportunity of familiarizing themselves with the opera- tion of automation instruments in the mines of the Krasnoarmeiskugoli mining and ore combine. A seminar on "Applications of radioisotope methods and instruments in the chemical process industry" was held in the "Atomic Energy" pavillion of the Exposition of Achievements of the National Economy of the USSR in September, 1971. The seminar attracted 112 representatives of 40 chemical and petrochemical plants, scientific-research institutes, organizations, and design agencies. The purpose-of the seminar was to promote exchanges of experience and information on the development of new radioisotope hardware, and on the implementation of radioisotope techniques and instruments in various branches of the chemical pro- cess industry. The reporters drew attention to the increased number of studies and projects in applications of radio- isotope instruments in the design of automatic process control systems, as well as the development of Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 93-94, January, 1972. ? 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 104 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 nuclear physics techniques for monitoring the composition and properties of chemical products, and im- plementation of full-scale industrial methods for monitoring chemical processes with the aid of radioactive tracers. Several chemical process plants and combines are already making use of a hundred or more radioisotope instruments each, with appreciable savings and improvements in working conditions as a re- sult. The seminar participants acknowledged the need for more widespread acceptance of radioisotope in- struments in chemical production processes, in order to facilitate further expansion of the utilization of the achievements of applied nuclear physics in the chemical process industry, with emphasis on their use in the production of mineral fertilizers, in the plastics industry, in synthetic fiber production, in the pro- duction of ore processing raw materials, and in chlorine industry, where they be used to maximum economic effect. On the initiative of the Ministry of Public Health of the USSR and the Moscow Scientific-Research In- stitute for X-Radiology, a seminar on "Modern techniques and equipment for radiation therapy of malignant neoplasms and clinical dosimetry" was held in September, 1971 at the "Atomic Energy" pavilion of the Ex- position of Achievements of the National Economy of the USSR. Participating in this seminar were 130 ra- diologist-physicians (radiation therapists). Of these, 80 were representatives of therapeutic?prophylactic and scientific-research institutes in the republics of the Union. The seminar participants heard reports in which the present state of the art and the developmental outlook of radiation therapy and clinical dosimetry were examined. The seminar participants recommended holding of future seminars on medical radiology. The feasi- bility of scheduling a symposium on diagnostics and treatment of lymphogranulomatosis was pointed out. A scientific-technical conference on "Applications of radioisotope instruments in the national economy" in October, 1971, was held in the city of Dushanbe. There were four panel sessions at the conference. The conference participants heard over 40 papers and reports discussing applications of radioisotope techniques and instruments in the ore and mining industry, in the building materials industry, cotton growing, medicine, and other fields. The reporters noted that the Dushanbe reinforced concrete structures and structural parts plant is making successful use of radioisotope equipment and techniques, with appreciable gains in the engineering costs picture. Methods of nuclear geophysics are being used effectively in expeditions and laboratories of the Geology Board of the Council of Ministers of the Tadzhik SSR. The Institute of Plant Physiology and Bio- Physics of the Academy of Sciences of the Tadzhik SSR worked out a method for autoradiography of cotton plants, and completed work on control of the transport of plant assimilants. Radioactive isotopes and sources of ionizing radiations are being used effectively in some medical institutions in Central Asia for diagnostics and treatment of various illnesses. The conference contributed to exchange of experience on the applications of radioisotope equipment in the national economy, and more widespread implementation of scientific-research developments in in- dustry. 105 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 CONFERENCES SIXTH ALL-UNION CONFERENCE ON SYNTHESIS, PRODUCTION, AND APPLICATIONS OF SCINTILLATORS L. Ya. Zhil'tsova, E. N. Matveeva, and I. M. Stoletova The regular VI All-Union conference on the synthesis, production, and applications of scintillators was held in May, 1971, in Khar'kov. A large number of the papers submitted to the conference dealt with research and development work in the physics of the scintillation process in alkali halide crystals. A paper by L. M. Shamovskii and col- leagues dealt with the nature of light diffusion centers and the conditions governing their formation in the process of growing ionic crystals from a melt. The nature of light-scattering inclusions was studied in the case of melt-grown fluorite crystals produced under a variety of melt conditions. It was shown that elimination of light-diffusing inclusions brings about improved scintillator quality. A report by E. M. Arm et al. dealt with the outlook for utilization of scintillation detectors with a base of CsI(Na) single crystals at elevated temperatures. They established the advantage of these scintil- lators over CsI(T1) scintillators. The scintillators investigated display a plateau in their counting charac- teristic at temperatures 140-150?C. A large number of papers were devoted to investigation of the proper- ties of these crystals. In line with the expanding opportunities for applications of CsI(Na) crystals, we note an interesting paper submitted by I. I. Kisel' and N. I. Krainikov on growing CsI(Na) single crystals in a horizontally rotating ampule. It was demonstrated that the growth rate of the single crystals can be in- creased above five times over the rates used in growing single crystals by the Stockbarger method. Single crystals grown at a rate of 11 mm/h are not inferior in their scintillation characteristics to the best single crystals grown by the Stockbarger method at a rate of 2 mm/h. B. K. Damitov et al. proposed a new method for determining the intrinsic resolution of small-size NaI(T1) crystals by using a photomultiplier with a large photocathode diameter. A report on an improvement in the technological process in mass production of polystyrene scintilla- tors was submitted by a team working at the VIIMonokristallov (All-Union Scientific-Research Institute of Single-Crystals) (0. A. Gunder, A. L. Lifshits, others), covering investigations of the technological factors influ- encing the polymerization process and the scintillation properties of plastic scintillators, and presenting recom- mendations on how to best fabricate them. G. P. Volosyuk et al. gave an account of the effect of such secondary solvents as naphthalene on the optical and scintillation properties of element-containing (heteroorganic) plastic scintillators, which are capable of raising the light yield of plastic scintillators by 30-35% when secondary solvents are used and luminescence additives are selected. 0. A. Gunder and colleagues studied the effect of vinylxylene synthesis technology on the light yield of plastic scintillators. It was demonstrated that an isomer of 2,4-dimethylstyrene exhibits the best scin- tillation properties. Research on polymethylmethacrylate base plastic scintillators has been continued (S. A. Malinovskaya et al.). Shortening of the fluorescence decay time and simultaneous increase in the amplitude of the light pulse with increasing concentration of luminescent additives have been detected. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 94-95, January, 1972. o 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for 815.00. 106 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 A. E. Buklei et al. developed and investigated a 1000 x 1000 x 20 mm counter based on such a plastic scintillator of enhanced transparency. The counter efficiency was measured with a beam of relativistic ir-mesons, and found to be close to 100% over its entire area. Many of the reports presented were read at the panel on applications of scintillators and detectors based on scintillator crystals. A report by V. V. Chernikov (in the name of a team of colleagues at VNIIMonokristallov) was devoted to a slow-neutron activation detector using plastic and liquid scintillators containing chlorine, bromine, iodine, and zinc. Introduction of iodine into plastic scintillators proved most successful. Neutron record- ing efficiency was 0.61 when plastic scintillators with a base of styrene and 10% diiodobenzene copolymer was used. A liquid neutron detector with an efficiency 0.66 was obtained by the authors upon introducing a tributylphosphate solution of InC13 into a-methylnaphthalene. E. M. Burymov reported on applications of platelet type deuterated scintillators in fast-neutron spec- trometry. Deuterated anthracene or naphthalene can be used as the platelet material. This scintillator, in the form of a stack of alternately sandwiched deuterated (0.05 mm) and glass (0.1 mm) wafers, can pro- vide an amplitude resolution of 1.3% and a peak-to-valley ratio of 30. During the conference discussion, investigations of scintillators as detectors of long-wavelength x- ray emission and of new scintillation detector units for x-ray equipment came under discussion (V. R. Al'per- ovich et al.), as well as enhanced sensitivity in recording of ultraweak bioluminescence of living tissues (E. V. Buyanov et al.), utilization of a low-background scintillation Y-ray spectrometer for investigating radiation purity of several materials (V. D. Gorin), investigations of the characteristics of scintillation detectors with the aid of light generators (Yu. N. Kuzin et al.), and so forth. Topics relating to the solu- tions of those problems received a prominent place in the discussion. A report by E. I. Minsker on optical adhesives with a polyorganosiloxane base was considered of great practical interest. The conference proceedings will be published in the next collection of articles in the series "Single Crystals, Scintillators, and Organic Phosphors" issued by VNIIMonokristallov, Khar'kov. The next confer- ence, the seventh, is scheduled for 1974. 107 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 FOURTH CONFERENCE OF THE INTERNATIONAL NUCLEAR DATA COMMITTEE M. F. Troyanov The regularly scheduled IV conference of the IAEA International Nuclear Data Committee (INDC) was held in July, 1971, at the Homi Bhabha Atomic Research Center in Trombay (India). The conference was attended by 14 INDC members, 13 representatives of various countries plus one IAEA representative, in addition to six scientific advisors and observers. The conference was opened with welcoming remarks by the director of the Center, H. Setna, who emphasized the importance of nuclear data in the development of atomic science, particularly for India. An isochronous cyclotron is being built in India (at Calcutta) to aid nuclear physics research there, and a pulsed fast reactor is also under construction (near Madras). The INDC conference agenda began with communications from the representatives of the several coun- tries, dealing with work on nuclear data measurements made and reported over the past year. The basic findings on new measurements were reported at the conference on neutron cross sections held in the USA (Knoxville, State of Tennessee, March, 1971), and at a neutron physics conference held in Kiev (May, 1971). Written reports of the activities on nuclear data studies in various countries are on file at the Ob- ninsk nuclear data center. Neutron standard data came under discussion at the INDC conference. Current "standards" for this work are the nuclides H1, He3, Lis, Bio, C12, u235. The importance of working out a system of recommended data on standards was stressed, and agreement was reached on the free exchange of estimated data on nu- clear standards. This means that the estimated data on the nuclides mentioned, obtained in various labora- tories throughout the world, will be made available for general use. The committee reviewed the status of the most important nuclear data, and discussed the principal discrepancies found in the fund of data. It was reported that recent measurements of fission spectra at Argonne and Karlsruhe have confirmed the Los Alamos data. An opinion was expressed on the need to con- duct additional integrated experiments to secure information on fission spectra. In that connection, IAEA scheduled its August, 1971 conference of specialists to discuss the findings of fission spectrum measure- ments. Disparities in the determination of the number of secondary neutrons emitted in spontaneous fission of Cf252, which still eludes explanation, were discussed. The measurements will have to be continued, using a variety of methods. A suggestion was advanced to measure the energy dependence of the ratio of the capture cross section of gold to the fission cross section of plutonium, with the object of clearing up some discrepancies in the fission cross sections of PU239 and U235. A review paper authored by M. Sowerby (Britain) and V. Kon'shin (USSR) dealt with analysis of a set of experimental values of the ratio of the radiative capture cross section to the fission cross section (a) of the nuclide PU239. This review paper analyzes results reported by various authors, and suggests the rec- ommended data. A protracted discussion followed the presentation of reports on neutron data, particularly in the light of the interaction between INDC and the Working Team on nuclear structures and reactions organized under Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 95-96, January, 1972. C 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 108 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 IAEA sponsorship. The committee stressed the fact that neutron data retain unquestioned priority in any nuclear data work, and that the entire activities of the team must be directed primarily toward the solution of applied problems, with the team working under the supervision of INDC. The conference heard reports on the work of nuclear data centers and on exchange of experimental information between four such data centers. A conference of the four centers was held in October, 1971 at Brookhaven, facilitating thorough discussion of their activities. The INDC IV conference discussed compiling a list of inquiries on nuclear data. At the present time several inquiry formats, including some developed in the USSR, have been submitted to IAEA. In the com- ing months all of these inquiries will be incorporated in a general list broken down by sections: reactors, thermonuclear fusion reactors, system of guarantees. These lists will be revised on a basis of roughly once every two years. The INDC conference heard reports on nuclear data estimates activities. The agreement reached on free exchange of estimated data based on "standards" is a first step on the path to free exchange of all es- timated data based on "standards" is a first step on the path to free exchange of all estimated data. To smooth the free exchange of these data and reach agreement on approaches to estimating techniques, IAEA prepared and scheduled a conference of specialists on the subject for August-September, 1971. A seminar on estimates of nuclear data was called in Rumania for the summer of 1972. In 1972, IAEA will be holding a conference on neutron "standards," and in 1973 a symposium on the acquisition, compilation, estimates, and dissemination of applied nuclear data, to be followed by the III general nuclear data conference sched- uled for 1974. 109 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 INTERNATIONAL CONFERENCE ON ELEMENTARY PARTICLES I. A. Savin The International Conference on Elementary Particles was held in Amsterdam (Holland) from June 30 to July 6, 1971 under the auspices of the Dutch Ministry of Education and Science and the University of Amsterdam, with the support of the European and Dutch Physical Societies, and the active participation of CERN. The work of the Conference was centered on plenary meetings with raporteur's talks on broad topics preceded by parallel section sessions where reports of original work ormini-rapporteur's talks on original works were heard. The Conference was attended by 590 scientists from many countries. About 440 original experimen- tal and theoretical papers were discussed. The plenary sessions were concerned with the following topics: high energy hadron physics (G. Gia- comelli, H. Zats), medium energy hadron dynamics (R. Barluto, M. Deutchman, and R. Phillips), low energy hadron physics (H. Dalitz, K. Shmid), weak interactions (K. Winter), electromagnetic interactions (E. Drell), and hadron symmetry (K. KaHan). Two invited talks were heard: on the status of the CERN proton?proton colliding beams (ISR) (K. Johnson) and on electron?muon universality (V. Telegdi). The raporteur and invited talks will be published. The more interesting experimental results reported at the conference are outlined below. High energy hadron physics was represented, in the main, by work done at IFVE (Serpukhov) on the 70 BeV accelerator and by preliminary results from the ISR. The results of measurement of the 7+, K+ and proton total cross sections on protons and deuterons was at the center of attention of the conference, particularly the discovery at Serpukhov that the K-Fp total cross sections grow at high energies. Much interest was aroused by the relatively slow decrease in the rthp interaction cross section difference [Aut(71-Ip) 120-1?2]. According to other data from IFVE the total charge-exchange cross section decreases with increasing energy at much faster rate (crex P-1.2) up to 50 BeV. It was pointed out in discussions that there must be a change in the energy dependence in the 200 BeV energy range or the well-known inequality 04702 const uex would be violated. Thus, the results of measurement of positive particle total cross sections together with the previously verified results on negative particles imply that the total cross section differences for r?p, KTp, and p?p continue to decrease with increasing energy. It follows that speculations about the possible violation of the Pomeranchuk theorem were premature. Another direct method of verifying theories of the behavior of scattering amplitudes, and in particular of measuring the behavior of the difference of total cross sections was used in an experiment performed at IFVE by a group from Dubna in conjunction with groups from countries participating in OIYaI (HPR and ChSSR). This consisted in measuring f, the amplitude for transmission regeneration of K1-1(95 on hydrogen, whose imaginary part is proportional to ,Ao-t (14I?? lep), the difference of the K9p and K9p total cross sections (or through isotopic spin invariance len and K-n). The results indicate that the modulus of the regeneration amplitude 1111/K if" while its phase (41) is constant in agreement with Regge model calculations and dispersion relations. It follows from these results that Aut (K9 ? R9p) decreases with Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 96-97, January, 1972. 0 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 110 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 increasing energy in agreement with requirements of the Pomeranchuk theorem. More accurate data will be available in the near future on the energy behavior of If1 I and arg ((p?21) from American (3-10 BeV/C) and Dubna (10-42 BeV/C) groups. Much time was given at the conference to the presentation of preliminary results from the ISR. The greatest interest was aroused by the announcement that the slope parameter (b) of the pp diffraction cone has different values at a given center of mass energy S for different momentum transfer intervals (for in- stance, for S = 2800 BeV2, b equals 12,8 ? 0.2 and 11.6 ? 0.15). This apparently reflects a decrease in the growth of b as compared with extrapolations of the results of the Dubna group at the IFVE accelerator to ISR energies. This fact implies that the effective proton radius ceases to grow at very high energies. Many papers were devoted to medium energy hadron dynamics. First of all, we consider papers on elastic scattering. The combined data shows that the pp and ep diffraction cones shrink with increasing energy up to ?-? 25 BeV/C, 7r+p shrinks slowly, pp shrinks and then reaches a plateau, while K-p does not shrink at all. At large momentum transfers the cross sections have a complex behavior with minimums and maximums. Some of these were observed for the first time. For backward scattering there are peaks for all reactions except pp. Elastic lrp scattering is iden- tical to pp scattering up to momentum transfers of 6(BeV/C2). The polarization of p?, 7r?, and K? scatter- ing on protons has been studied in detail. Among papers on inelastic two-body scattering, we note the first results on pp ? EZ,E+1+, 27r, and 2K reactions. The first reaction exhibits a forward peak in the angular distribution, while the second has a forward peak and a break in the angular distribution for t= ?1.2 (BeV/C)2 together with a break in the po- larization in the same region. Quasi two-body reactions were represented by papers on the angular distributions and exchange dy- namics of definite strange and nonstrange states for processes of the type Ic-p A+K*-, PK*-, nK*? (890 MeV/C2), PK*-, nK*? (1420 MeV/C2), K-p Ap, Aw, p, E? K?p A++K?, ep A++ co, etc. for which information was obtained regarding the angular distributions and dynamics of exchange through specific singular and nonsingular states. The study of many-particle reactions was represented by two methods: exclusive reactions, i.e., experiments where the parameters of all particles are fully determined, and inclusive reactions, where the characteristics of one (or two) particles are studied and the parameters of the remaining finite system are summed over (missing-mass type experiments). Definite success has been achieved in the study of exclusive reactions due to the use of van Hove's LPS procedure (decreasing the number of variables by summing over the perpendicular momenta). An ex- change hierarchy o-(P) > o(M) > o(S) > a(E) has been established for both total and differential cross sections were P, M, S, and E indicate vacuum, mesonic, strange, and exotic poles. All the cross sections except for those proceeding through P exchange diminish with increasing energy. Inclusive reactions were analyzed in terms of the hypothesis of scale invariance according to which cross sections at high energies depend only on PI and the ratio X = /Pmax. This hypothesis was tested in a large energy region including ISR energies. Scaling invariance holds for certain reactions (pp ? 7r+ ; pp p + ...) while it is obviously broken for others (K?p K? + ? X + or holds in a limited region of X (ep 1r + , r+p ? 7r+ . . . ) Low energy hadron physics was represented at the Conference by papers studying the characteristics of resonances. ?Reports were heard on the systematic study of baryon resonances in K+N interactions. Resonances have been observed in the Aar, 7r- , * (1385 MeV/0, 7r, and Er systems. There are indica- tions of the existence of a strangeness +1 resonance in the reaction K?d K?pp with M = 1760 MeV/C2 and = 300 MeV/C2. The existence of a AY resonance with a mass of 1327 MeV/C2. in the reaction ic-p 71-0Ay has not been substantiated. Two groups, ITEF and CERN, have also reported observation of a resonance in the per+ system (1700 MeV/C2). New information on boson resonances has been found. One of the most important results is the ab- sence of splitting in the A2 meson as determined by high-statistics experiments at CERN and Brookhaven. Also of interest is the joint IFVE and CERN work on the energy dependence of boson production cross sections. The A2 meson production cross section is constant over a wide momentum range (25-40 BeV/C) while the R meson either disappears completely from 10 to 25 BeV/C or has a factor of ten decrease in its production cross section. 111 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Weak interactions, which have been intensively studied by experimentalists and theorists since 1964, when CP-invariance was found to be violated in KL? + 7r- decays, were again generating broad interest. The effort of many years by physicists to measure the modulus and phase of the parameters 74_ and noo, which are the branching ratios for the KL and 4 neutral and charged two pion decay, would seem to have ended in 1970 when ITEF and OIYaI groups established reliably that koo I 174_1. This result was con- firmed at the Conference by a CERN group whose results were In00/74_ I = 1.00 ? 0.06. Taken together with the mean weighed values of the phases 900/9_, = 0.99 ? 0.25, this means that the superweak interaction the- ory which explains the mechanism of CP-invariance violation is correct. It follows from this theory that there should be no CP-violation effects except in KL decays. This has held true up to the present despite the vigorous efforts of experimentalists to find other CP-violating decays. An experiment recently performed at Berkeley which established the upper limit for KL 11+12- (5 1.8 ? 10-9) decays was discussed at the Conference. This limit is several times lower than the possible theoretical limit which is estimated using electromagnetic interactions on the basis of the previously shown decay probability K ry confirmed at the Conference by an ITEF group. If one assumes both results to be correct, then one can expect that the new result is tied to another manifestation of CP-violation. From the remaining data on the properties of weak interactions, the work of a CERN group concluding the long effort to verify the AS = AQ rule in leptonic decays of le mesons should be noted. It has been shown experimentally that this rule hold to an accuracy of a percent in 43 decays. 112 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 FOURTH INTERNATIONAL CONFERENCE ON PLASMA PHYSICS AND CONTROLLED NUCLEAR FUSION B. B. Kadomtsev and V. D. Shafranov The Fourth International Conference on Nuclear Fusion of the IAEA was held in June, 1971, at the University of Wisconsin at Madison. About 600 scientists from about 30 countries participated in the con- ference, and about 140 reports were heard. Most of the reports were delivered by the rapporteur system. The conference dealt with the results of work in controlled thermonuclear fusion over the last three years. As in previous conferences, most of the work has been experimental. The conference opened with a session on studies of plasma behavior in toroidal traps having inner conductors ? levitrons and multipoles; reports on an astron were also heard. At one time it appeared that devices having internal conductors would significantly simplify studies of physical properties of plasmas in a toroidal geometry, since a deep magnetic well, which should lead to a prolonged stable confinement of the plasma, can be easily produced in such devices. Unfortunately, this turned out not to be so. The quite complicated behavior of the plasma in multipoles has necessitated a prolonged and persistent study which has not yet led to a common point of view regarding the mechanisms for plasma escape. Nor was a common point of view reached at this conference. For example, in studies carried out at the University of Wisconsin with two octupoles ? a small one with supports and a larger levitating octupole, it has been shown that the plasma is subject to an anomalously rapid escape at a rate of the order of the Bohm rate. This anomalously rapid plasma escape may be associated with small perturbations from in- homogeneous external fields. It was reported in other studies that the plasma confinement time in an oc- tupole reaches 300 Bohm times; collisional diffusion approximately three times as rapid as classical dif- fusion is observed at a high plasma density, and only at low densities do the additional losses associated with the imperfections in the magnetic field and the plasma loss at the supports become apparent. Preliminary data indicate that the imposition of a toroidal magnetic field does not reduce the collision- al diffusion of the plasma as is expected on the basis of "neoclassical" theory; in other words, so-called pseudoclassical diffusion is observed. This expression is now used for the semiempirical dependence of the transport coefficients proposed first by L. A. Artsimovich (USSR)for the electronic thermal conductivity, which is proportional to the collision frequency and the square of the Larmor radius corresponding to the "poloidal" (azimuthal) magnetic field. S. Yoshikawa et al. (USA) have observed in a levitated spherator that the plasma decays after emission at decay times approximately equal to the classical values, but they observe increased diffusion during the plasma heating. Other studies of traps having internal conductors have been concerned with such topics as the isola- tion of supports by current flow within them, plasma stabilization by freezing of lines of force at the plasma boundary, oscillations in the stable-confinement regions, the formation of convective cells associated with inhomogeneities in the neutral-gas flow, etc. Reports on the astron device dealt with electron accumulation in a E layer, the equilibrium of this layer, and its stability along with that of the plasma. Theory shows that the flute instability cannot be avoided in the ordinary astron, so the astron modification having an additional toroidal magnetic field is to be preferred. The resulting system is actually similar to a tokomak operating in the escaping-electron mode. One astron version having a toroidal magnetic field is an astron spherator, proposed in a report by S. Yoshikawa and N. Christophilos (USA). It has been found possible to invert the magnetic field within a ring formed by relativistic electrons in a small model at Cornell University. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 98-101, January, 1972. 0 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 113 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 There was much interest in tokomaks (two complete sessions were devoted to these devices). Ex- perimental results found in studies of plasma behavior at the new T-4 and T-6 tokomaks (I. V. Kurchatov Institute of Atomic Energy) and the TS tokomak (Princeton University), were reported and there was a dis- cussion of the theory of plasma properties in tokomaks. The experimental results reported demonstrated progress in the study of plasma parameters and of the mechanisms operating in plasmas. For example, the achievement of an electron temperature of 3 keV and an ion temperature above 0.6 keV was reported by L. A. Artsimovich, V. S. Strelkov, et al. (USSR) in studies with the T-4 device, which is based on the T-3. This became possible because of a significant current increase achieved by overcoming the barrier at q = 3 (q = rBz/RB0 is the so-called stability re- serve, where r and R are the minor and major axes of the torus, and 13, and Bo are the toroidal and azi- muthal magnetic fields) and by converting to smaller q values, as low as q = 2 (according to preliminary data, values as low as q = 1 have sometimes been achieved). The physical bases of the possible change to lower q values were clarified in a report by S. V. Mir- nov and I. B. Semenov (USSR), who reported correlation measurements of corkscrew instabilities in plas- mas. It was shown that instabilities of mode m arise in a plasma when the q value at the plasma boundary approaches integral values of m. Between these values there are wide stability regions, so that by rapidly changing the current and going by the critical q values, one can reach stability regions having smaller q. These results correspond well to theoretical ideas about the resistive nature of corkscrew instabilities of modes having m> 1 (V. D. Shafranov). These results also show why it is possible to pass the critical q values only at a high plasma conductivity. Interestingly, precisely these same results regarding the de- velopment of the corkscrew instabilities at the edge of a plasma were found in studies with the Princeton TS tokomak. Identical results were obtained with these two devices on another subtle effect ? the kink or disruptive instability: a series of sharp negative spikes in the time dependence of the loop voltage, accompanied by plasma expansion. This instability, observed in all tokomaks, is initiated as the current channel is con- tracted (e.g., due to corkscrew perturbations or neutral-gas cooling of the plasma periphery, and when the plasma is displaced along the major radius). However, the nature of the instability has not yet been resolved. H. Furth and P. Rutherford (USA), e.g., analyzed the natural assumption that the m = 1 mode develops within the plasma, but it turns out that the negative voltage spikes cannot be explained in this manner. It should be kept in mind, incidentally, that the quasilinear approximation was used in this study, while according to the experimental data of Mirnov and Semenov (USSR) there is a random, turbulent spec- trum of magnetic perturbations at the instant of the disruptive-instability outburst. As was mentioned above, experimental results obtained with the T-3 and T-4 devices, on the one hand, and the TS device, on the other, display an agreement which is rare in plasma studies. However, there are some discrepancies. One concerns the radial dependence of the electron temperature: in the TS device this temperature has a sharper maximum at the center of the plasma than in the T-3 and T-4 devices. Furth reported that this discrepancy could be caused by a temperature instability: the radial temperature distri- bution turns out to be extremely sensitive to slight perturbations, e.g., in the netural-gas flux from the chamber walls. Another discrepancy is in the conclusions regarding the diffusive flux. In the T-3 and T-4 devices, the diffusive flux is reported to be much less than the thermal flux, while in the TS device these fluxes are comparable. This discrepancy will probably require refinement of the calculation of the diffusive flux in the T-3 and T-4. In regard to the magnitude of the plasma escape we find for the ionic thermal conductivity a good agreement with the neoclassical value (except perhaps for the "banana" region of very low collision fre- quencies), while the electronic thermal conductivity (and, in the TS device, diffusion) is much greater than neoclassical, while the thermal-conductivity coefficient is roughly proportional to the collision frequency and independent of the toroidal magnetic field. A special term was even introduced for this dependence, which was proposed previously by Artsimovich on the basis of an analysis of experimental data: "pseudo- classical diffusion (or thermal conductivity)." Yoshikawa showed that a slight random inhomogeneity of the plasma, due, e.g., to drift instabilities, can lead to pseudoclassical diffusion. He also reviewed many ex- periments in toroidal devices, including some in stellarators, in which diffusion may be interpreted as pseudoclassical. The conference heard some results of studies carried out at the recently completed TO-1 and T-6 tokomaks in the Institute of Atomic Energy (USSR); these devices differ structurally from the "traditional" 114 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 tokomaks. Instead of a conducting sheath to maintain the plasma at equilibrium in the TO-1, there is a system which automatically regulates the transverse confining field. In the T-6 the conducting sheath is within the evacuated chamber. The spectrum of neutral charge-exchange atoms escaping tangent to the wall of the torus has been measured in this device, and it has thus been possible to prove the isotropy of the ion temperature. Interferometric measurements have shown that the plasma density profile is accentu- ated in the discharge, and the density increases at the axis. This new effect may be due to the pinching of toroidally trapped particles discussed in a report by A. Ware (USA). The conference heard theoretical reports on the equilibrium and stability of a toroidal plasma and the recent developments in neoclassical theory. A. A. Galeev and R. Z. Sagdeev (USSR) carried out a detailed study of the role of impurities in neoclassical theory. M. Rosenbluth (USA), L. M. Kovrizhnykh (USSR), and T. Stringer et al. (Great Britain) have derived a systematic theory for plasma revolution in a toroidal magnetic field and have studied its role in the diffusion. In particular, they have shown that revolution along the minor, rather than the major, azimuth along the torus plays the more important role when longi- tudinal viscosity is taken into account. The theoretical reports took up certain effects described by neo- classical theory: the plasma pinching, the related additional heating, the temporal evolution of the plasma, etc Working on the basis of neoclassical theory, B. B. Kadomtsev and Shafranov (USSR) showed that the diffusive expansion of a low-density plasma results in movement of a poloidal magnetic field toward the periphery. As a result, when a sufficiently large ratio of the plasma pressure to the pressure of the poloi- dal magnetic field is reached, it becomes possible to maintain a longitudinal current in a tokomak by a sin- gle diffusive flux, without an external vortex electric field. In this manner a steady-state (instead of pulsed) tokomak becomes possible, differing little in this regard from a stellarator. An analogous idea was ad- vanced by R. Bickerton, J. Taylor, and 0. Connor (Great Britain). Although the tokomak data found in various laboratories were found to be similar, the stellarator data remained extremely contradictory. Several years back in conference discussions, one frequently heard the expression "Munich mystery" for the sharp contradiction between classical plasma confinement at the Wan- delstein stellarator at Munich and the anomalously rapid plasma decay with a Bohm time at stellarator S. Today, not only has this "mystery" not been resolved: the number of contradictions has even increased. One gets the impression that stellarators can be classified into a group in which classical confinement is observed and into a group in which there is an anomalously rapid decay. A very nearly classical confinement (within a factor of two to four) has been observed in the Proto- Cleo device, in which the collisionality parameter, i.e., the ratio of the loop length to the mean free path, was varied over five orders of magnitude. Classical confinement has also been observed in Saturn 1, in which the dependence of the confinement time on the neutral-gas pressure has been measured. In a study carried out under similar conditions and in the presence of a neutral gas, V. I. Volosov observed anoma- lously rapid plasma leakage governed by the development of instabilities of the drift type. Japanese phys- icists have also observed anomalously rapid decay of plasma accompanied by the excitation of drift-type fluctuations. Diffusion an order of magnitude more rapid than classical has been observed in a heliotron. These contradictory results on confinement have not yet been resolved. Presumably plasma confinement, at least at a very low density, is very sensitive to small changes in the field geometry and the parameters of the device, so that it can easily enter a region of unstable confinement. It is satisfying in this connection to note that in the transition to higher densities and temperatures in the Uragan device the behavior being observed has much in common with that of the plasma in tokomaks. Specifically, although the confinement time is much less than classical, the results have been in qualitative correspondence with those found in tokomaks: the energetic lifetime is governed by the anomalous electronic thermal conductivity (almost two orders of magnitude greater than the classical thermal conductivity), while the diffusion time has been much greater than the energetic time. The lack of agreement on the basic question of mechanisms for plasma leakage has not stopped stel- lerator studies of subtler physical phenomena. Soviet reports dealt in detail with the increase in the plasma decay rate near values of the rotational-transformation angle corresponding to closing of the lines of force. It was shown that the increased leakage is due to the development of convection in the plasma. An experi- mental study has been made in the Liven-1 stellarator of the development of a quasistationary ion flow in the plasma, apparently due to the formation of departure cones in the ion distribution function. A detailed study of turbulent plasma heating in a stellarator was also reported. 115 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300-100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Thirteen reports were delivered to the session on open traps, covering the most recent and deeper studies of leakage mechanisms and physical properties of the plasmas in adiabatic traps. Successful studies have been made of plasma parameters [a temperature of up to 106 eV at a density of 1012 cm-3 in a hot-elec- tron plasma (R. Dandl et al., USA) and an ion temperature of up to 8 keV at a density of 5 -101.3 crif-3 in a hot-ion plasma in the 2X device] and the processes in plasmas. Some studies were devoted to plasma instabilities. D. Sweetman et al. (Great Britain) showed that the threshold for cyclotron instability in a hot-ion plasma is governed by Landau electron damping. They have observed capture of an injected neutral beam in a confined plasma. The cyclotron instability of a low- density plasma was also studied by M. K. Romanovskii, N. N. Brevnov et al. (USSR). M. S. Ioffe (USSR) reported that the plasma in the PR-6 device, having a density of 1011 cm-3 and an ion energy of about 1 keV, decays anomalously rapidly because of an instability of the cone type, which turns out to be extremely sensitive to the plasma potential (this instability is excited when the potential is increased). As yet no ade- quate theoretical description of this effect has been reported. Studies of z-pinches were discussed. Dutch and British physicists have succeeded in improving the z-pinch stability with a longitudinal magnetic field. Theoretical stability studies by D. Robinson have shown that magnetic field configurations exist in which the plasma is hydrodynamically stable at currents much larger than those attainable in tokomaks. The essential question here is whether the conditions necessary for stability can be arranged. According to the classification proposed by H. Bodin et al. (Culham, En- gland), pinches stabilized by longitudinal magnetic fields can be divided into three groups according to sta- bilization method: the screw pinch, in which the stabilizing longitudinal field increases at the same time as the current in the plasma does; the "stabilized pinch," in which there is a paramagnetic distribution of the longitudinal magnetic field; anad a pinch with an inverted (outside the plasma) longitudinal magnetic field. Unfortunately, the experiments which have been carried out so far by Bodin and colleagues have been devoted only to the stability itself, which sets in under the conditions predicted by theory. The maxi- mum plasma temperature, of the order of 100 eV, according to data from experiments carried out both at Culham and at Julich and Garching (West Germany), is found in the screw-pinch mode. The high tempera- ture is retained for only a short time, however, because of the rapid decay (in 20 Asec) of the discharge current. Van der Lane et al. discussed the reasons for this rapid current decay. In recent years there has been much interest in 0-pinches, in which quite high plasma parameters have been achieved. Numerous results found with linear 0-pinches were reported at the 1968 Novosibirsk conference. However, these results were flawed because of the presence of end losses and the hydromag- netic instability of a 0-pinch of finite length. The 0-pinch configuration has now been changed; the linear systems have given way to toroidal systems, which are similar to stellarator or tokomak systems. The first experimental results were reported on 0-pinches of toroidal geometry ? in a spatially peri- odic magnetic field with protective annular conductors (Nagoya University, Japan), in a tokomak configura- tion with an elongated elliptical cross section (Julich), and in a corkscrew configuration corresponding to a single-turn stellarator (Garching). F. Ribe reported experimental heating and confinement of a plasma in the 5-m toroidal sector of the Scyllac device at Los Alamos. The first experiments have shown the va- lidity of the theoretical prediction of a possible counterbalancing of the toroidal extension of the plasma through the combined use of a spatially periodic field and a single-turn corkscrew field. Freiberg showed that the experimental absence of the second and higher perturbation modes predicted on the basis of MHD theory was due to the finite size of the Larmor ion radius. Definite progress in the study of plasma-focus physics was demonstrated at the conference. Rayleigh ?Taylor instability of the focus has been observed, the ion energy has been measured on the basis of light scattering, the temporal dependence of the soft x-radiation has been studied, and the angular distribution of the neutron radiation has been studied. Calculations by Potter and Haines have shown that the ion velocity distribution at the focus axis may become highly anisotropic. This result is apparently a key to the ex- planation for the observed anisotropy in the neutron emission from a plasma focus. Several reports were devoted to the possible creation of a thermonuclear plasma by means of intense electron beams (Babykin et al., USSR) and laser beams. Calculations and some first experimental results on laser heating of a solid target were reported by others. J. Dawson et al. (USA) proposed a thermonu- clear reactor with magnetic thermal insulation based on a long-wave N2- CO2 gas laser. 116 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 A long session (22 reports) was devoted to theoretical and experimental studies of collective turbulent phenomena in plasmas. A detailed review of turbulent plasma heating incorporating new results found from noise measurement in plasmas was given by K. E. Zavoiskii et al. (USSR). Other reports dealt with the results of a detailed study of turbulent plasma heating under various conditions. These results are gener- ally in agreement and lead to the conclusion that ion-acoustic oscillations play the leading role in producing the anomalously high plasma resistance. However, electron beams appear in the plasma, either simul- taneously with the ion sound or at alternate times, and the beam-plasma interaction which arises compli- cates the pattern of turbulent processes. The interaction of electron beams (including relativistic beams) with plasmas have been studied at Khaekov, Prague, Oak Ridge, and Novosibirsk, where many interesting results have been found on the physics of this beam-plasma interaction and on energy transfer from the beam to the plasma. In particular, it has been shown that in the interaction of an intense beam with a plas- ma the heating is achieved by a reverse current induced in the plasma. Several reports were devoted to the theory of anomalous plasma resistivity [L. I. Rudakov and D. D. Ryutov (USSR) and W. Drummond (USA)]. Some new experimental results were reported on rf heating of a plasma during propagation of electro- magnetic waves in it, and new ideas regarding the use of rf fields in plasma heating were reported. One aspect of the conference which reflected the clear progress in controlled-fusion research was the session on reactor systems. In the corresponding reports, hypothetical reactors were discussed on the basis of existing plasma-confinement systems: tokomaks, stellarators, open traps, etc. Analysis of the engineering problems involved in thermonuclear reactors is already necessary, to furnish a basis for better evaluation of the outlook for various research directions. 117 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 BRIEF COMMUNICATIONS The State Committee for Utilization of Atomic Energy of the USSR organized a "scientific familiariza- tion visit" to the Soviet Union from August 5 to September 7, 1971 for groups of specialists from member countries of the International Atomic Energy Agency with the theme, "Use of isotopes and irradiation in agriculture." Representatives from Cuba, Rumania, Poland, Chile, the UAR, Cyprus, India, Ceylon, Iran, Iraq, Ethopia, Burma, Uraguay, and other countries took part in the visit. This arrangement was made through facilities granted voluntarily by the USSR from the technical aid funds of the International Atomic Energy Agency. One-day seminars were organized for the participants during the visit on the problem of use of iso- tope tracers in studying the fertility of soil at different levels, use of stable N13 and radioactive P32 isotopes, and the adoption of radiation technology in agriculture. The specialists from abroad visited and learned about the research works of the V. I. Lenin All-Union Academy of Agricultural Science, the V. V. Dokuchaev Soil Institute, the Timiryazev Agricultural Academy, the All-Union Research Institute for Electrification in Agriculture, the All-Union Research Institute for Fertilizers and Agronomic Soil Science, the Department of Soil Biology of the Moscow State University, the Leningrad Agrophysical Research Institute, the Ukrainian Research Institute for Plant Physiology at Kiev, and the Institute of Cytology and Genetics of the Ural Branch of the Academy of Sciences of the USSR at Novosibirsk. * * * A return delegation of Canadian specialists on reactor materials, headed by Dr. Hart, was received in September, 1971 in the Soviet Union. The Canadian specialists visited the I. V. Kurchatov Institute of Atomic Energy, the Khar'kov Physical- Power Institute at Obninsk, the Atomic Reactor Institute at Melekess, the Beloyarsk nuclear electric power station and the "First Nuclear Power Station in the World." They became acquainted with the work of Soviet scientists and specialists on vacuum extrusion of uranium, zirconium, niobium, and tantalum; with findings on the properties of zirconium alloys working in boiling liquid conditions; with the technology for extrusion of cladding materials from zirconium alloys and their inspection; with the particular features of the struc- ture of zirconium alloy with 1% niobium; with problems on hydrogen absorption and corrosion in a neutron field in a boiling medium. The Canadian delegation were interested in work on structural materials for fast reactors and for low-power reactors for use in the far-North. At the concluding meeting with the State Committee for Use of Atomic Energy in the USSR, opinions were exchanged between the Soviet and Canadian specialists on the problems examined. A recommendation was expressed regarding the provision of scientific seminars on a defined range of problems. * * * An International School on High Energy Physics for Experimental Workers was held from 13 to 27 June, 1971 and the Joint Institute for Nuclear Research together with the Bulgarian Academy of Sciences and with participation from the European Organization for Nuclear Research (CERN), not far from Varna, Bulgaria. The object was to acquaint young experimental physicists with the contemporary state of theo- retical physics. Translated from Atomnaya Energiya, Vol. 32, No. 1, pp. 101-102, January, 1972. O 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 West 17th Street, New York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever without permission of the publisher. A copy of this article is available from the publisher for $15.00. 118 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 ? The scientific program was in three parts: 1) a basic course of lectures devoted to the theory of strong interactions and multiple production and also problems of extreme nonelastic electron?proton in- teractions; 2) specific problems in the theory of relativistic equations, duality and Venetsiano's model; 3) the scientific work of the Joint Institute for Nuclear Research, the high-energy laboratory of the Joint Institute for Nuclear Research, the Institute for High-Energy Physics at Serpukhov, and work at CERN. Seminar tasks were set on the basis of the lectures. The main course of lectures was given by D. V. Shirkov (JINR), Zh. Prentki (CERN), V. S. Bara- shenkov (JINR), A. Byalas (Poland), Nguen Van Quey (Vietnam) (in a lecture written jointly with A. A. Logunov), 0. Kofed-Khansen (CERN), and V. A. Matveev (Dubna). Prominent in the program of scientific research were: the Vice-Director of JINR, A. Mikhul and the Director of the High-Energy Laboratory at JINR, A. M. Baldin; the Corresponding Secretary of Institute of High-Energy Physics, V. A. Yabra (with a report written jointly with the Director of the Institute, A. A. Logunov) and the Director of CERN, V. Entchke. The total number of participants was 109 from 21 countries. Their training was not all alike ? more than half those who took part had virtually no experience in research work and approximately 1/3 of the par- ticipants had been occupied in research work for three years or more. The school succeeded in the main task of acquainting young experimental physicists with contemporary aspects of theoretical physics. In the opinion of Soviet participants the school was of great value. Mention should be made of the excellent organization of the school and the warm welcome extended by our Bulgarian friends to all those who attended. The proceedings of the school are being published by the Joint Institute for Nuclear Research in two volumes. 119 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 ( Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 ; I Declassified and Approved For Release 2013/03/01 : CIA-RDP10-02196R000300100001-0 A New Bimonthly Journal Covering Man-Made Fibers FIBRE CHEMISTRY A cover-to-cover translation of Khimicheskie voiokna, a periodical,organ of the Ministry of the Chemical Process Industrybf the USSR k ????. Editor-ih-chief: G. I. Kudryavtsev Editorial Board: N. Ya. Alekhin, A. G. i3orshakov, A. L. .Borisov, A. G. Borik, A. G. Grigoeyants, V. A. Gruzdev (Deputy Chief Editor), S. 1... Dich, A: A. Konkin, A. P. Krainov, R V. Kupinskii, B. A. Mukhin, N. V. Mikhailov, E. M. Mogil- evskli, B. V. Petuichov, A. B. Pakshver, Z. A: Rogovin, and A. T. Serkov (Deputy Chief Editor). Translated from the Russian This bimonthly journal, devoted to furthering the growth of artificial ',fibre production, will provide- access to Soviet and non-Soviet advances in the science and technology of fibre synthesis. The journal describe's the present state Of the industry, and its future prospects, discusses=theoretical and prac-, tical progress in the production of all-types of artificial fibres, and presents the most im- portant advances in research on Macro- molecular compounds suitable for the manu- facture of fibres. It deals with the develop- ment of new processes, the mechanization and automation of individual operations, the designs of new equipment, the planning "and modernization of plants, the economics and organization of production, and quality con- trol. All those concerned with the science and technology of man-made fibre produc- tion will find this English language edition a valuable reference source. Selection of articles from issues 1-5, 1968 CONTENTS: Polymerization of acryloni'trile'in presende of the potasdium persulphatesodium metabisulphite 'system, N. M. Seder and V. A. Meglitskii. Influence of the molecular weight of polythene on fiber formation and properties,' A. A. Aver'yanov, D. V. Fil'bert, and A. A. Konkin. Supermolecular structure of graft-modi- fied cellulose fiber& T. S. Sydykov, L. S. Antonyiik: R. M. Lilishits, and Z. A. Rogovin. Prevention of foam- . , \ ing in thse spinning,and finishing baths in manufacture of high-strength viscose coed, V.1