Gigawatt microwave from an intense relativistic electron beam

Microwave generation experiments were carried out on a multimegavolt electron accelerator (3.3 MV, 80 kA). X-band microwave power as high as approximately 1 GW was measured. Results are compared with a non-linear theory of unstable resonant interaction between a TE waveguide mode of the electron drift tube and an electron cyclotron wave on the beam.