Operation Of A Quasi-Optical Gyrotron With Variable Output Coupling

Results from a quasi-optical gyrotron experiment with a 20-28 cm mirror separation will be presented showing operation from 95-130 GHz at powers up to 150 kW and efficiencies up to 11%. The output coupling can be controlled by varying the mirror separation. Efficiency optimization by variation of output coupling and by tapering the magnetic field has been demonstrated.