Characterization of laser produced hot electron propagation via coherent transition radiation in cold and warm dense aluminum

Abstract

Coherent transition radiation is used to evaluate fast electron transport of a laser-driven relativistic electron beam in ultrathin targets in selected materials. By preheating the targets with a low-intensity laser pulse, the bulk resistivity effects on electron transport in heated and unheated aluminum foils were compared with those in polyethylene (CH) foils. Unheated aluminum foils showed a pinched electron beam that was 50% smaller than the laser full-width at half-maximum focal spot. On the contrary, it was found that in preheated material Al and unheated CH, both materials with high bulk resistivity, the hot electrons experienced greater divergence and reduced energy.