Experimental research on X-band superradiant relativistic backward wave oscillator

Background Superradiant relativistic backward wave oscillators (SR-RBWOs) typically utilize electron beams with a pulse width of several nanoseconds. The required pulse source features small volume and light weight, which provides a feasible technical approach and implementation scheme for the development of compact high-power microwave systems. Superradiant microwave pulses are characterized by a fast-rising edge, high peak power, and wide bandwidth, which are expected to better satisfy the application requirements in complex electromagnetic environments.

Purpose In this paper, an X-band SR-RBWO with extend slow wave structure operating at a strong magnetic field is designed, which can simultaneously achieve stable operation and high conversion efficiency.

Methods And experimental investigations were carried out using a compact Tesla-type pulse source experimental platform.

Results The experimental results demonstrate that under the conditions of a diode voltage of 283 kV, a current of 3.25 kA, a pulse rise time of 1.8 ns, and a guiding magnetic field of 3 T, the generated SR pulse achieves a power of 840 MW with a conversion factor of 0.91. The pulse full-width at half-maximum (FWHM) is 1.2 ns, the operating center frequency of the device is 10 GHz, and the microwave is radiated in the TM₀₁ mode. Stable operation is realized at a repetition frequency of 50 Hz.

Conclusions The experimental results provided a reference for further experimental verification of low magnetic field SR-RBWO.