SPONTANEOUS AND STIMULATED-EMISSION IN MICROWAVE-OSCILLATORS WITH A VIRTUAL CATHODE

A one-dimensional model of electron beam emission with a virtual catho de is used to show that spontaneous emission occurs in a reditron whil e stimulated emission is observed in vircators and negative triodes. H owever, at a certain stage in the latter, the radiative instability is quenched as a result of the evolution of turbulence in the electron b eam. The idea is therefore put forward that this quenching may be elim inated by specially shaping the leading edge of the high-voltage suppl y pulse to the diode of the microwave oscillator. (C) 1998 American In stitute of Physics. [S1063-7850(98)02502-6].