Development of a MW-level Dual-frequency Gyrotron for Fusion

A 105GHz/140GHz MW-level gyrotron has been developed aiming for fusion application at Institute of Applied Electronics. The gyrotron employed a triode magnetron injection gun, a cylindrical cavity working under a TE18,7 mode for 105GHz and a TE24,9 mode for 140GHz. A built-in quasi-optical mode converter, a single-stage depressed collector and a boron nitride single-disk window were adopted in the tube. In the short-pulse (1ms) proof-test, due to limitation of the high-voltage power source, the dual-frequency gyrotron achieved output powers of 300kW at 105 GHz and 540kW at 140 GHz, respectively.