IAEA-182 EXPERIMENTAL ASPECTS OF LASED RAN ELECTRON-BEAM PRODUCED THERMONUCLEAR PLASMAS PROCEEDINGS OF AN ADVISORY GROUP MEETING EXPERIMENTAN O L ASPECT LASEF SO D RAN ELECTRON-BEAM PRODUCED THERMONUCLEAR PLASMAS HEL TRIESTET DA , 25-29 AUGUST 1975 ORGANIZED BY THE INTERNATIONAL ATOMIC ENERGY AGENCY TOG ETHER WITH THE INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS, TRIESTE A TECHNICAL DOCUMENT ISSUED E BYTH INTERNATIONAL ATOMIC ENERGY AGENCY, VIENNA, 1976 PLEASE BE AWARE THAT MISSINE TH AL F LO G PAGES IN THIS DOCUMENT WERE ORIGINALLY BLANK IAEe Th A doe t maintaisno n stock f reportso thin si s series. However, microfiche copies of these reports can be obtained from INIS Microfiche Clearinghouse International Atomic Energy Agency Kamtner Ring 11 0 59 P.Ox Bo . A-1011 Vienna, Austria on prepayment of US $0.65 or against one I AEAmicrofiche service coupon. D R W0 E R 0 P The Advisory Group Meeting on Experimental Aspects of Laser and Electron-Beam Produced Thermonuclear Plasmas was organized by the Agency together with the International Center for Theoretical Physic follow-ua Triesten i ss e wa th t f I .o p Worksho Theoretican po l Problem f Laseo s r Blectron-Beam Plasma Interactio nTrieste helth t da e Cente Augusn i r t 1973 scientist7 2 . s from 10 countries attended the meeting. meetine e coursfirse th dayo th th f e preseno stw f n t gI th o e t f experimento t ar e statlasen th electron-bea o d sf eo an r m produced plasmas were reviewed by the representatives of several major laboratorie includee ar d san thin d i s publication. Workshop-type sessions on the following selected topics were held? 1. Laser systems 2. Interaction of laser beam with target plasma 3* Laser heating for magnetic confinement &» Diagnosti f implosioo c n 5. Reactor concepts. Short resumes of these sessions prepared by the chairmen together with four original papers presented at the meeting are included in this report. The participants also exchanged their possible viewth n o s e rol f smalleeo r experiment e lase electron-bead th an rn i s m fusion programme with the aim to give guidelines to developing countries which would lik staro et t researc thin hi s field. The facilities provided for this meeting by the ICTP were excellent and the Agency would like to acknowledge the personal efforts of Professor Budini and Dr. Hamende of the Center who contributed to the success of the meeting. Tabl Contentf eo s NATIONA LABORATORD LAN Y REPORTS Laser fusion Laser fusion researc Japan hi n C. Yamanaka Laser fusion research at the Lebedev Institute of Physics of the USSR Academy of Sciences ............................ 5 V. Gribkov Laser fusion research at Los Alamos .••••«•«•«•••••••••••••••••• 9 1 Mc1 . 0 H Ca . Review of BRDA inertial confinement fusion efforts ............. 21 G. W. K u s w a Laser fusion research at the Centre d1 Etudes de Limeil,Franee .. 27 J.P. Babuel-Peyrissac and J.P. Watt e a u Laser fusion research in UK «•»••••••*•••••••«••«*•*••••«•**•«•• 29 . SpaldinJ . I g Laser research at the Institute of Applied Physics, University of Bernei Switzerland »•»»••••••»•••»•••»••»••••»•••••»•••»• H. W e b e r Electron-beam produced fusion Research at the I.V. Kurchatov Institute of Atomic Energy on the powerfuf o e us l electron beam initiato st epulsea d thermo- L. I. Rudakov Electron beam researc Sandit ha a Laboratories, USA. ............3 4 . sa n o G .Y REB Institutfusioe th t na Plasmf eo a Physios, Nagoya University, ^•••"••••••••••••••••••••••••••••••••••••••••••••••*N .. A Ja.na.t i * 49 SUMMARIES OF THE SESSIONS H* J* D o u c e t Interaction of laser radiation with plasma ••••••••••••••••••••• 55 P. Sigel and V. S i 1 i n Laser heatin magnetir gfo c confinement ••••••••••••••••••••••••9 5 • I. Spalding Implosion diagnostics using X-rays .•••«....•..•••••»«•»•••••••• 63 J.P. Babuel-Peyri s s a c and G. W. K u s w a role smalleTh f eo r experiment lasee th rn s i fusio n programm • e• 65 M. Gryzinski CONTRIBUTED PAPERS Laser interaction with plasma ••«•*••••••»»«••*•••«•••«**•«••••• 69 ad , hi s o Y . K , i k a s a S . gn T , a K . H , . i MJ i zu T.Tschudi, N. YamaguchijT. Yamanaka, C* Yamanaka Plasma heatin intensy gb e relativistic electron-beam ..........5 9 . K. ImasakitS. Nakai , C. Yamanaka Some reactor implication lasef so relativistir r(o c beam)7 fusio10 • n• I. Spalding Laser induced non-linear plasma phenomena (self phase modulation of light) and anomalous absorption of REB in plasma ••••••••••••••• 113 C. Yamanaka List of participants •••••••••••••••••••••••••••••••••••••••••••••• 117 NATIONA LABORATORD LAN Y REPORTS Laser Fusion LASER FUSION RESEARCH IN JAPAN C. Yamanaka Institute of Laser Engineering, Osaka University, Osaka Summary? The following main aims are being pursued in the field of laser fusion researc Institute th t ha f Laseeo r Engineering, Osaka IfoiversityJ - Developmen f higo t h power high efficiency lasers - Stud f physicyo f laseo s r coupling with plasma.. - Development of diagnostics of fine spacial ( /urn) and temporal (psec) resolution ' - Development of technique of a pellet compression* High power Nd glass laser GEKKO syste E-bead man m excite . lasedCO r LEKKO system are being developed for these purposes. GEKKO I - one beam glass laser system with 7 amplifiers, energy output , lasens 2 r n beai J m 0 diamete5 ms 0 i m4 wits i r hdivergenca e being less than 0.5 m rad, pulse widt s adjustablhi e tenfrow mfe s picosecondo t s nanoseconds. GEKKd GEKKan OI O I e correspondingl IVar four-bead an o ytw m systems with an energy of 250 J in each beam. A twelve-beam glass laser wit htota a 0*n i 5J l K nse energ0 s 1 i c f yo being planned. The results achieved with the GEKKO system up to-day are the following: Parametric decay instabilit s yclarifiei d experimentally inducee Th . d backward Brillouin scattering observed nea e seconth r d harmonice th f o s reflected light shows an isotope effect due to the ion acoustic waves in hydrogen and deuterium plasma respectively. A decrease of the reflectivity of the laser light from plasma was ascertained at the laser intensity of ten times larger than the threshold of the parametric decay instability. Spectral broadenine self-phasth o t e gdu e modulatio observes e nwa th n di backscattered wavelengte lighth n i t h 1.06 /urn. Acceleration mechanismf o s fast ion was investigated. A compression experiment is investigated using glass micro balloon filled with D_ gas. LEKKO I - is high pressure E-beam C02 laser with two stages of TEA laser preamplifie three-staged an r mai2 sC0 n amplifier outpue th n !i J t 0 energ20 s yi one nanosecond. LEKKO III, a two-beam system to deliver 1 KJ in one nanosecond is under construction. +) Composed from records of oral presentation 3 The following results have teen obtained wit e LEKKhth O systems Anomalous heatin parametrio t e gdu c instability has been clarifiede Th . threshold laser power intensity for this process is 101Q W/cm2* Below .the threshol e expansiodth s nthermai l powewhica s hha r dependenc f fto e4 /9, where Q is the incident laser flux. Above the threshold the expansion is flux-limited which shows a power dependence of Q£/3, A control technique of oscillating line double-lasey sb r cavity wit hsaturabla e absorbe bees ha rn accomplished* The pressure broadening coefficien e CC>th 2 f la-seo t r lin s ederivei d froe mth small signal gain dependenc lase n pressurs eo ga r e using 5 atmosphere pressure E-beam C(>2 laser* a 3 LASER FUSION RESEARCH AT THE LEBEHEV INSTITUTE OP PHYSICS, USSR ACAIEMST OP SCIENCES V. Gribkov Basov'n I s Laborator e Lebedeth f yo v Institut e probleeth f mo thermonuclear fusio lasey nb s seei r s consistinna followinge th f go : I* Creatio optiman a f no l laser-target system ensurin gmaximua m amplification coefficient: V Developmen. II preparatiod tan targete th f no . This must ensure high average density in the final cumulation state: 10 -f-10 g/cm , and hav largea e initial fuel mass (DP, CUT, LigDP): 10. g ~ ,-2 III. Achievement of a maximum oonyers ion coe f fioient from laser energy to kinetic energy of the collapsing material: IV. Creation of such cumulation dynamics that the density and temperature profiles before the beginning of combustion are as follows: TkeV I02ll0 10 i• 10 . ObtaininV g stabilit compressioe th f yo n process* 5 H.Gn I . Basov*s Laboratory these problem beine ar s g solvee th n di following way: . I Powerful lasers neodymiun O ) (a m glass (1) A 9-channel device has been operating since 1971 , , contrasJ ns T0 , 1 a&10 a 50 (0 E a 1 t rad) (2) In 1974 a 20-channel laser device was started up. ; kJ 2 T J k J 41 0 20 (Ea T a 2 x 10"11 s r 10~9 s f 2 x 108 s, contras 1x 0 , 0 3 1 $ta rad) 216-channe(3A ) l devic s beini e g built which will be started up at the end of 1976, though one quarte f 197ro wil d 5operatine en b l e th y gb (E = 10 kJ, T a 1 ns, luminosity 1017 W/cm2 sterad). (b) iodinn Thera s ns)i e1 a lase. T , rJ operatin0 13 a E g( f 197 o e energd 5Towardth en ye wilth s l increaso et 500 J.