Development of 100-second ECRF system for JT-60SA

Moriyama, Shinichi; Kobayashi, Takayuki; Isayama, Akihiko; Yokokura, Kenji; Shimono, Mitsugu; Hasegawa, Koichi; Sawahata, Masayuki; Suzuki, Sadaaki; Terakado, Masayuki; Hiranai, Shinichi; Igarashi, Koichi; Sato, Fumiaki; Wada, Kenji; Shibayama, Minoru; Hinata, Jun; Shinozaki, Shinichi 

The electron cyclotron range of frequency (ECRF) system (3 MW 5s at 110 GHz with 4 gyrotrons) of JT-60U will be upgrade to the system having 9 gyrotrons (7 MW 100s) for JT-60SA (super advanced). As heat removal from the mirrors is essential for a long pulse antenna, a new concept with a mirror driven in the linear motion which eliminates the flexible tube for coolant supply is under development. The design study featuring beam profile calculation showed feasibility of the antenna in the 0.48 m 0.48 m port. The low power rf test with simple mockup antenna has just been begun. Aging of the gyrotron with improved mode converter was started in the end of 2008, aiming at 1 MW, 100s oscillation. Because the current capacity of the present high voltage power supply is not enough to realize 100s oscillation, LHRF power supply having twice larger current capacity is connected to the gyrotron in March 2009. The gyrotron aging will be started soon again.