RECENT RESULTS FROM STUDIES OF ELECTRON-BEAM PHENOMENA IN SPACE PLASMAS

Experiments involving the ejection of beams of electrons from spacecra ft have been performed for more than 2 decades in order to study funda mental plasma physical processes as well as for a range of diagnostic- and application-oriented purposes. This paper reviews some of the key issues that have been pursued in the past 10 years. These include que stions regarding spacecraft charging and beam dynamics. the interactio n of beams with neutral gas and plasmas, and the electromagnetic radia tion generated by continuous and pulsed electron beams. It is shown ho w our understanding of these phenomena has matured, thereby providing a solid foundation for future experiments involving the use of electro n beams.