Nichtstationäre Reflexion und Reemission von Wellen bei Herausbildung elektromagnetischer Strukturresonanzen im Plasma

Abstract

The nonstutionary resonant reflectivity of a density profile is studied which consists of two homogeneous overcritical layers, separated by i i vacuum region whose width increases linearly in time. Analytical expressions are derived for the time dependence of both the reflexion coefficient and the crivity field in the case of normal incidence. If the configuration pisses through n structure resonance, where the eigenfrequency of the density cavity coincides with the frequency of the external wave, the cavity field is strongly enhanced. The temporniy f o r m h o n und the subsequent decay of this resonant field leads to oscillations of the reflexion coefficient. I n the case of ;I loss-less plasma it may reach the extreme values \RI&in = 0, IRlkas w 3 and the moving plasma configuration temporarily acts as nn energy storage (;Biz < 1) or nn emitter (,RI* > 1).