Observation of Stimulated Raman Scattering from 20-psec Laser-Produced Plasmas

Abstract
Raman scattering spectra obtained with 20-psec 1.064-μm laser pulses incident at 45° on nickel-foil targets show an intensity-dependent red shift relative to the subharmonic of the laser frequency. In conjunction with temperature data deduced from x-ray measurements, the results imply a change from the absolute to the convective instability with increasing intensity. The observation of Raman scattering is correlated with the appearance of a high-energy tail in the x-ray spectrum above 100 keV.