An electron cyclotron maser for nanosecond megawatt pulses

Abstract
An electron cyclotron maser with an output power of 1 MW in the X-band has been constructed. The device uses a relativistic electron beam with a radial electron density distribution similar to Gaussian, not annular as usual. The nonadiabatic perturbation of the magnetic guide field is produced by a single iron ring of 57 mm axial length. Measurements are reported of reproducibility, peak power and frequency-spectrum as a function of electron energy and magnetic field strength. The results presented are interpreted as far as possible using existing theories.