Studies on a new dual-coaxial vircator

A dual-coaxial vircator without an external magnetic field is proposed and studied in this paper. By the use of a coaxial energy extraction structure, the beam-wave interaction and energy extraction processes can be carried out separately. The left end wall of the inner conductor of the extraction structure can reflect microwaves and, thus, provides a feedback mechanism for the beam-wave interaction; it can also absorb the electrons drifting in the outer space of the interaction region. The two characteristics are of benefit to the improvement of the output power and efficiency. Using a voltage pulse with peak value of 500 kV, output power with instantaneous peak value of 2.5 GW and period-averaged value of 1.2 GW are obtained by simulation at 2.175 GHz, the efficiency reaches 11%.