Laboratory Simulations of Controlled Energetic Electron-Beam-Plasma Interactions in Space.

摘要

Recent laboratory investigations of space simulated electron beam plasma interactions have concentrated on the transition from single particle behavior to collective plasma processes with emphasis on the beam plasma discharge. The plasma has been characterized with respect to its spatial distributions in density, temperature and density fluctuation power spectra. The latter results have been further classified in terms of amplitude and spectral distributions. The overall results include: (i) detailed radial profiles of plasma density as a function of beam parameters; (ii) the association of low frequency large amplitude fluctuations with ion acoustic, ion cyclotron and drift wave modes; (iii) the identification and spatial mapping of suprathermal electrons in the beam core; and (iv) the experimental definition of a density dependent criterion for the ignition of the beam plasma discharge. The data provide a synoptic perspective on accumulated rocket observations and meaningfully contribute to planning activities for future space borne applications of artificially injected energetic electron beams.