On the Extrapolation of Space-Simulation Beam-Plasma Investigations to Shuttle-Borne Applications

摘要

Laboratory simulations of space plasma phenomena provide an important link in establishing broader perspectives of various plasma processes, in helping to understand spatially or temporally limited rocket and satellite observations, and in planning future spaceborne experiments. One such area has been the artificial injection of energetic electron beams in space which has transitioned from an early and somewhat confused set of rocket data through a relatively intensive program of laboratory based space simulations, to an ambitious program which exploits the Shuttle as a readily accessible laboratory in space. While accumulated information points to a considerably improved understanding of beam plasma parameters which define single particle behavior on the one hand and collective beam plasma properties on the other, the extrapolation of these results to Shuttle borne applications is met with a number of constraints. Focusing on the transition from single particle behavior to the collective nonlinear interactions in the beam plasma discharge, this paper provides a comparative analysis on aspects involving Shuttle unique environmental effects. Emphasis is placed on Shuttle potentials and associated sheaths, ambient plasma and neutral density effects including relative spacecraft motion, pulsed versus dc gun operation, and beam plasma discharge criteria in general.