Microwave experimental simulation of laser plasma interactions. Combined quarterly status report, October 1, 1978--April 30, 1979

This program continues to stress the use of high power microwave sources (lambda0 = 1-30 cm) and large diameter quiescent laboratory plasmas in the investigation of the absorption and transport of energy in laser-pellet interactions. The large spatial scalelengths (1-4 m) and relatively long time-scales (10 nsec-10μsec) permit the careful measurement of localized electric and magnetic fields as well as particle energy and density. During the past seven months we have focussed our attention on experiments designed to address two problems of particular relevance to the laser fusion program. The first experiment has been concerned with an investigation of stimulated Brillouin scattering (SBS) in the underdense regions of the blow-off plasma. A separate experimental investigation aimed at an understanding of the generation of quasi-static magnetic fields was carried out. In this effort we are concerned with the production of magnetic fields in the vicinity of the critical layer due to resonance absorption, nonparallel temperature and density gradients and parameteric instabilities