Development of a high power CW waterload for Gaussian mode gyrotrons

A high power waterload was developed for use with Gaussian mode gyrotrons producing output powers up to 1.25 megawatt (MW) CW between 70-170 GHz. This paper describes the electrical and mechanical design and provides the results of initial tests on a gyrotron at 110 GHz. The load uses a rotating reflector and a tapered dielectric loss coating to control the power absorption within the cylindrical structure. Test results indicate that the load may be capable of significantly higher power levels than anticipated and that the load may be able to reliably dissipate power levels approaching 2 MW CW.