Hot-electron characterization from<i>K</i>α measurements in high-contrast,<i>p</i>-polarized, picosecond laser-plasma interactions

Abstract

Strong K\ensuremath{\alpha} emission is observed in picosecond laser-plasma interactions with high-intensity-contrast, p-polarized, picosecond laser pulses. K\ensuremath{\alpha} emission from Si substrates overlaid with various thicknesses of Al is compared with a Monte Carlo simulation. The results show that the hot electrons which deposit their energy in the solid material have a 3-keV temperature and carry 10% of the incident laser energy. The shifted K\ensuremath{\alpha} emission indicates that the solid is heated to a temperature of 35 eV up to 5000 \AA{} from the target surface, which is consistent with the preheat of the hot electrons.