Further design steps towards a 4 MW 170 GHz coaxial-cavity gyrotron

It is desirable to increase the RF power per gyrotron tube for plasma heating in future fusion devices. The realization of gyrotrons with highest possible output power will reduce their overall number and superconducting magnets required for future fusion reactors. In this work the feasibility of a 4 MW 170 GHz coaxial-cavity gyrotron is investigated. A mode selection procedure is presented and proper designs of major gyrotron components are shown. A possible outer wall corrugation of the cavity is discussed and possible improvements are shown. Further electron gun studies are performed using diode- and triode-type magnetron injection guns (MIGs). First layouts for the two-cut launcher are considered.