Dynamics of an electron beam with a virtual cathode in a vircator without a magnetic field and with drift space filled by neutral gas
The physical processes in a vircator without an external magnetic field and with a drift space filled by neutral gas are studied. Three typical dynamic regimes are found: (1) the suppression of virtual cathode oscillations, (2) pulse generation, in which the suppression and resumption of virtual cathode oscillations are observed, and (3) continuous virtual cathode generation. The frequency dynamics of the vircator’s output radiation is investigated for the last case, and it is shown that the generation frequency of the vircator can rise when the gas pressure exceeds a certain critical value.