We present measurements of the fast-electron-relaxation time in short-pulse (0.50.3em0exps) laser-solid interactions for laser intensities of 10¹⁷, 10¹⁸, and 10¹⁹0.3em0exW∕cm², using a picosecond time-resolved x-ray spectrometer and a time-integrated electron spectrometer. We find that the laser coupling to hot electrons increases as the laser intensity becomes relativistic, and that the thermalization of fast electrons occurs over time scales on the order of 100.3em0exps at all laser intensities. The experimental data are analyzed using a combination of models that include Kα generation, collisional coupling, and plasma expansion.
No takes yet. Share an insight, caveat, or question.
Chen et al. (2007) studied this question.