H.F. emission related to particle beams injected into ionospheric plasma from spacecraft

During active injection of an electron beam, and charged neutral beams consisting of ions and electrons into the ionosphere from a spacecraft a broad spectrum of waves is generated. The characteristics of these emissions change substantially with altitude, beam current and ratio of ambient plasma to electron cyclotron frequencies. Many of rocket and satellite experiments performed up to now, have clarified the nature and features of these waves. This paper is concern with a particularly interesting aspect of these experiments, namely the high frequency (h.f.) wave generation. copyright 1996 American Institute of Physics