Fraction and Temperature of Hot Electrons Generated by Laser-Plasma Interaction at the Shenguang-II Laser Facility

We have developed a three-dimensional electron-photon Monte Carlo transmission (MCT) code. The conversion-transmissivity coefficient of hot electron x-ray, η_ct, is analysed theoretically and simulated numerically using the MCT code. Experiments of disc and cylindrical targets have been performed at the Shenguang-II laser facility. A multi-channel filter-fluorescence spectrometer was used to obtain the hard x-ray spectrum. The temperature and energy of hot electrons are induced from the hard x-ray spectrum and the η_ct value. The average energy fraction of hot electrons is 14% of incident laser energy for the 1ωN_d laser and the spherical target, and the average temperature of hot electrons is 36keV, while 15% for the 1ωN_d laser and the cavity target with the average temperature of 54keV. Also, we obtained the results of 5.6% and 13.3 keV for the 3ωN_d laser and the disk target, 4.9% and 17.9keV for the 3ωN_d laser and the half cavity target with a thin wall, and 2.1% and 22.45keV for those with a thick wall. The experimental results agree with theory and simulation.