USE OF LARGE SCALE-LENGTH PLASMAS TO STUDY PARAMETRIC PLASMA INSTABILITIES

Apart from their intrinsic interest, plasma physics processes are impo rtant because they affect the coupling of the laser energy into laser- irradiated targets. Recently, new gas-filled targets have been develop ed to create large mm-size plasmas for the study of stimulated Brillou in scattering (SBS) and stimulated Raman scattering (SRS). We present x-ray images and x-ray spectra to characterize these targets, which sh ow that the plasmas are homogeneous, have electron densities of simila r to 10(21) cm(-3), and attain electron temperatures of similar to 3 k eV. We also give SBS measurements to demonstrate how systematic studie s of physical phenomena can be performed using these targets.