Experimental Measurements of Hot Electrons Generated by Ultraintense ( > 10 19 W / cm 2 ) Laser-Plasma Interactions on Solid-Density Targets

We present the first in-target measurements of the electrons produced by an ultraintense (I{gt}10{sup 19} W/cm {sup 2}) laser pulse incident on a massive solid target. Total conversion efficiency, mean electron energy, and electron cone-angle measurements are presented. A relationship between the target material and the mean electron energy is also discussed. {copyright} {ital 1998} {ital The American Physical Society}