Experimental Research of X-band Dual-Frequency Coaxial Relativistic Backward Wave Oscillator

The design and experimental demonstration of an X-band coaxial dual-frequency relativistic backward wave oscillator (CRBWO) with sectioned slow wave structures (SWSs) is presented. In this paper, we describe the experimental measurement methods of frequency, power and operation mode for the high-power microwave signal. In experimental tests, with a 500 kV, 11.5 kA beam guided by a 0.82 T magnetic field, a microwave with an average power of 507 MW and pulsewidth of 50 ns has been obtained. Also, the dominant frequencies of the X-band dual frequency are 9.845 GHz and 10.517 GHz, and the dual-frequency difference f≈672 MHz, which was similar to the particle-in-cell simulation results. The operation mode of the device is determined to be TM01 mode in our experiment.