High power microwave generation by virtual cathode oscillator

Summary form only given, as follows. A new configuration of virtual cathode oscillator (vircator) has been studied for high-power microwave generation. In this vircator configuration, a resonant cavity is used to enhance the field-beam interaction in order to improve the microwave efficiency. Experiments were carried out on repetitive pulsed power generator ETIGO-IV (400 kV, 13 kA, 120 ns, 1 Hz). The output microwaves are diagnosed for peak power and dominant mode by using horn receivers and field probes, which are calibrated by a network analyzer. The microwave frequency is obtained by fast-Fourier transformation of the signal recorded by a high-speed digital oscilloscope. The initial experimental result has indicated a beam-to-microwave conversion efficiency of 9 %. Three-dimensional particle-in-cell simulations were carried out by using simulation code MAGIC. Simulation results are compared with experimental results to examine the effect of the cavity and possible ways of further improvement of microwave efficiency.