Efficient Raman sidescatter and hot-electron production in laser-plasma interaction experiments

These experiments studied the Raman instability occurring at densities below the quarter-critical density of the incident 0.53-μm laser light. Solid gold targets were irradiated by up to 4 kJ of energy in a 1-ns pulse with focal spots of 150 to 1880 μm. The angular distribution of the Raman scattering shows efficient Raman sidescatter. The energy in electron plasma waves accounts for the hot-electron production over almost three orders of magnitude. We report the results and discuss the implications for laser fusion