Subgigawatt Ka-band BWO with a Permanent-Magnet-Based e-Beam Focusing System: Experiments, Simulations, and Prospects

A study of a 38-GHz nonstationary relativistic BWO operating with an impulse solenoid has been performed. The production of subnanosecond pulsed microwaves with a peak power of ~500 MW with this BWO was carried out experimentally and using a PIC simulation. It has been shown that the topology and magnitude of the magnetic field best suited to focus the electron beam can be provided by a magnetic focusing system assembled of high-coercivity permanent magnets. This offers promise for this type of BWO to produce microwaves of more than 100 MW peak power at a pulse repetition rate as high as some tens or hundreds of hertz and even more.