A Power-Optimizing Integrated Design of a Dual-Frequency Gyrotron Quasi-Optical Mode Converter

The conventional design method for multifrequency gyrotron quasi-optical mode converters often results in excessive stray radiation within the gyrotron tube. A new design technique is introduced that integrates the designs of the launcher and mirror system of the converter and optimizes the mirror system for minimal diffractive losses. The new technique is applied to a redesign of a dual-frequency 110- and 124.5-GHz mode converter. It is shown that, by reoptimizing the converter with the new method, its diffractive losses can be reduced by 28.7% and 17.8%, respectively, at the two frequencies, whereas all of the other conversion properties of the output beams remained constant or improved.