Plasma Wave Observations During Electron Beam Experiments at High Altitudes

Electron beam experiments on the nearly geosynchronous P78—2 satellite conducted in 1979 resulted in observations of intense radiation near the local electron gyrofrequency. These signals resembled naturally occuring fCe waves during the same period. The amplitude of the stimulated waves depended upon beam parameters. During 50 eV beam operations, current levels of 10 pA produced strong emissions. Current levels of 1 pA and 100 pA did not. These emissions correspond in time to previously reported observations of electron distributions which suggest heating of the local thermal plasma. Sufficient power is in the observed emissions to explain the heated electron distributions observed during the experiments.