Measurements of the Parametric Decay of Co-Laser Radiation into Plasma Waves at Quarter-Critical Density Using Ruby-Laser Thomson Scattering

Abstract
We report the results of small-angle ruby-laser Thomson-scattering measurements of the parametric excitation of plasma waves by CO2-laser radiation at quarter-critical density in a laser-heated gas-target plasma. From supplementary data obtained from interferometry and large-angle ruby-laser scattering we infer that the threshold conditions for a convective decay are satisfied.