Influence of positive ions on oscillatory processes in an electron beam with virtual cathode

Research paper by R. A. Filatov, Yu. A. Kalinin, A. E. Khramov, D. I. Trubetskov

Indexed on: 01 Oct '06Published on: 01 Oct '06Published in: Radiophysics and Quantum Electronics


We numerically simulate the influence of positive ions on characteristics of the microwave oscillations in a nonrelativistic electron beam with the virtual cathode formed in a decelerating field (low-voltage vircator). A numerical scheme allowing for ionization of a residual gas by an electron flow is proposed. It is shown that the residual-gas ionization in the operating chamber of a low-voltage vircator leads to a forcing of the virtual cathode out of the transit gap and to a cutoff of microwave oscillations. The obtained numerical data are confirmed by an experimental study using a low-voltage vircator model.