A High-Power Backward-Wave Oscillator Driven by a Relativistic Electron Beam

A high-power backward-wave oscillator (BWO) has been constructed that is driven by a relativistic electron beam (REB). A typical electron beam of 2-4 kA is accelerated across a diode potential of 650-800 kV and then guided through a section of corrugated transmission line by an axial magnetic field of 5-15 kG. Peak microwave powers of 100-200 MW have been observed in the circular TM01 mode at the predicted frequency of 8.4 GHz. The basic principles and parameters of operation will be discussed, along with the dependence of peak microwave power on applied axial magnetic field.