Progress of high power 170 GHz gyrotron in JAEA

Sakamoto, Keishi; Kasugai, Atsushi; Kajiwara, Ken; Takahashi, Koji; Oda, Yasuhisa; Hayashi, Kazuo; Kobayashi, Noriyuki*

Recent progress on the high power gyrotron development in JAEA is presented. The gyrotron is featured to have a triode type magnetron injection gun, a cylindrical resonator working at 170 GHz with TE mode, a water-cooled diamond window and a depressed collector. After the demonstration of ITER basic performance, the gyrotron has been operated for 3 years, and recorded 200 GJ of total output energy. In the next, a gyrotron which oscillates at higher order resonator mode, TE, is designed and fabricated to study the long pulse oscillation at greater than 1 MW. In parallel, feasibility studies of a CW-power modulation for NTM (Neo classical Tearing Mode) stabilization, a dual frequency gyrotron and a rapid frequency control are carried out. It is shown that these gyrotrons will be available with present technologies.