High Altitude Plasma Effects. Parametric Excitation by an Electromagnetic Pump in a Large Laboratory Plasma (QUIPS: Quiescent Plasma Studies): First Results

摘要

A series of experiments are being carried out in the TRW large volume plasma facility, the QUIPS (Quiescent Plasma Studies) device. The purpose of the experiments is to study those parametric instabilities which are excited when high power microwaves propagate into a plasma cutoff region. The plasma instabilities have been observed with probes; in later experiments, Thompson radar scattering diagnostics will also be used. A variety of nonlinear effects which are consistent with the standard linear theory of parametric instabilities were observed, as well as other phenomena which are still the subject of theoretical study. The experimental results are grouped into the following topics: Parametric excitation of high frequency sidebands near the pump frequency; Excitation of low frequency oscillations; Propagation of ion acoustic waves in the presence of an electromagnetic wave pump; and Mode coupling of electron plasma waves and ion acoustic waves by an electromagnetic wave pump. (Author Modified Abstract)