(IT/2-4Rc) Development of the 170 GHz Gyrotron and Equatorial Launcher for ITER

K. Sakamoto1), A. Kasugai, K. Takahashi, R. Minami, T. Kariya, Y. Mitsunaka, N. Kobayashi
1) Japan Atomic Energy Agency, Naka, Japan

Abstract.  Recent progresses on the development of 170GHz gyrotron and an equatorial launcher are described. On the development of 170 GHz gyrotron, significant progress has been obtained. Up to now, stable 1 hour oscillation was demonstrated at the output power of 0.6 MW, which exceeds a discharge time of steady state experiment of ITER (3000 s). By optimizing the oscillation condition during the shot, the output power was enhanced up to 0.82 MW. The efficiency was 56 % with the depressed collector operation, and no trouble was found for 10min. The measured stray radiation in the gyrotron is 2 %, and the coupling efficiency with the corrugated waveguide is 96 %. In the design of the equatorial launcher, quasi-optical RF beam line was introduced. Consequently, the heat load on the movable mirrors due to the Ohmic loss of RF power was significantly reduced. These results give a clear prospect for an accomplishment of ITER ECH/ECCH system.

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