A repetitive X-band relativistic backward-wave oscillator

A repetitive X-band relativistic backward-wave oscillator (BWO) driven by a SINUS-881 accelerator is described. Relativistic electron beams with peak current of 5.4 kA and voltage of 610 kV at a repetition rate of 100 Hz were generated by the SINUS-881 and then guided through the corrugated waveguide by an axial magnetic field of 3.0 T produced by a superconducting magnet. An electron collector was used to collect the electron beams in order to mitigate the effect of secondary emission electrons and to prevent ionization and breakdown near the electron beam dump. This BWO produces a microwave pulse power of 1.1 GW at a 100-Hz repetition rate, a frequency of 9.38 GHz, a pulse duration of 23 ns, and a power transforming efficiency of 33%.