Powerful eximer laser systems with γ-pumping for plasma physics and ICF research in the 0.1- to 1.0-MJ energy range

Abstract

Results of experimental and calculation and theoretical investigations on eximer laser pumping by y-radiation powerful source is presented. Based on the results of investigations there are proposed laser systems for study of thermonuclear targets compression physics.In our earlier reports [1 ,2] we informed about use basic possibility for researches of inertial thermonuclear fusion and plasma physics research of high powerful gas lasers,pumped by y-radiation of a small (less than 1 kiloton)nuclear explosion. As a pumping source the nuclear explosion possesses a number of unique peculiarities essential for laser thermonuclear fusion problem. This is its small dimensions defining the pumping high space and time symmetry; high of rradiation density providing the pumping high specific power ( I 0-1 00 Me i7cm'); this is the pumping high specific power of laser gas medium (0.3-1 .5)J/cm. as well as high degree of pumping uniformity at E,> 1 MeV. These peculiarities are easily realized using the longitudinal laser pumping in onepuss "running wave" mode with synchronous propagation along active volume of medium excitation area by ?.radiation and laser pulse generation front. The medium excitation mechanism, at that, is consisted of y..radiation Comptonscattering and energy transmission to secondary electrons in recombination-nonequilibrium plasma. 252 SPIE Vol. 3268 • 0277-786X/98/$1O.OO Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/20/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspxGamma-pumped lasers have the advantagesaheir laser radiation pulses one can use without any conversion of their time and spectral characteristics. Duration and time structure of laser pulse at the use wrunning wave" mode with the longitudinal pumping is definitely determinate by fly-pulse, and if y-pulse duration rather small, it is necessary to form laser pulse with use of nonlinear optics elements, in addition. The possibility of direct pumping of short-wave eximer lasers exclude of the initial laser radiation spectral conversion and there occurs the possibility to produce systems with the laser radiation wavelength of large range. We shall explain these possibilities in detail lower.Experimental and calculation-theoretical researches performed YNIIEF were justified and formed the basis of our later proposals. Much attention is given to eximer and radiation-chemical lasers, in optimal way corresponding optimally the condition of the pumping by short y-pulse in the "running wave" mode. This is eximer UI/-laser on XeF* molecule (2. 0.35 1 irn) and radiationchemical IR-laser on XeF* molecule (? 3 urn) [3-6].Operation mixtures composition optimization and estimation of their spectral radiation characteristics have performed in laboratory investigations with excitation the small of active media by electrons of high current electron accelerators. Simultaneously with these investigations there were made calculation and theoretical estimations of the expected characteristics of eximer UV-lasers with y-ray pu...