Design of a high efficiency launcher and mirror system for use in a 110 GHz TE/sub 22,6/ mode gyrotron

A new launcher designed for a TE/sub 22,6/ mode at 110 GHz has nearly all of its power in a well collimated beam. A set of four beam-shaping mirrors without discontinuities has been designed to convert the output from this launcher to a Gaussian beam at an 88.1 mm diameter output window. The experimental fraction of power coupled to the output Gaussian beam is 99.0% with an overall system efficiency of 97.0%. Theoretical and cold-test results are presented.