STUDIES OF SUPRATHERMAL ELECTRONS IN HOHLRAUM TARGETS

Experiments of planar and cylindrical hohlraum targets have been conducted on " Shenguang" laser Facility in recent years. A multichannel filter-flourescer spectrometer was used to obtain the hard X -ray spectrum. The temperature and energy of suprathermal electrons were induced from the hard X-ray spectrum. When the energy of a single beam of incident laser is in the range of 400 - 670J, and the pulse duration in the range of 650 -1150ps, it is found that two groups of suprathermal electrons obey Maxwellian distribution (T_h = 35 - 45keV, T_hh= 150 - 350keV) in hohlraums, and total energy of suprathermal electrons E_he is about 10%-12% of incident laser energy. Experiments also show that E_he is fairly concordant with the amount of stimulated Raman scattered (SRS) light, so we can conclude that SRS is the primary mechanism for producing suprathermal electrons in hohlraum targets. Fraction of suprathermal electrons in hohlraum is bigger than that of planar. The results are analysed and discussed.