Author/Authors :
Saito، نويسنده , , K. and Mutoh، نويسنده , , T. and Kumazawa، نويسنده , , R. and Seki، نويسنده , , T. UEDA-NAKAMURA، نويسنده , , Y. and Ashikawa، نويسنده , , N. and Sato، نويسنده , , K. and Shoji، نويسنده , , M. and Masuzaki، نويسنده , , S. and Watari، نويسنده , , T. and Ogawa، نويسنده , , H. and Takeuchi، نويسنده , , H. and Kasahara، نويسنده , , H. and Shimpo، نويسنده , , F. and Nomura، نويسنده , , G. and Yokota، نويسنده , , M. and Takahashi، نويسنده , , C. and Komori، نويسنده , , A. and Zhao، نويسنده , , Y. S. Yoon، نويسنده , , J.S. and Kwak، نويسنده , , J.G.، نويسنده ,
Abstract :
During long-pulse discharges by minority ion cyclotron range of frequencies (ICRF) heating (majority: He++ and minority: H+) in the large helical device (LHD), phenomena of hot spots on antenna side protectors, localized divertor plate temperature increase and sparks from inner side of torus were observed. Plasma duration time was limited by the gradual or sudden density increase. The gradual density increase was due to outgassing from the graphite divertor plates or antenna side protectors with hot spots. The spark resulted in sudden density increase. It is thought that the localized divertor plate temperature increase and sparks are attributed to the high-energy ions accelerated in front of ICRF antennas. By suppressing these phenomena the world largest input energy was achieved.
Keywords :
52.40.Fd , 52.40.Hf , 52.50.Qt , ICRF , RF , Outgassing , Steady state , LHD
