Author/Authors :
Saito، نويسنده , , K. and Kumazawa، نويسنده , , R. and Mutoh، نويسنده , , T. and Seki، نويسنده , , T. and Watari، نويسنده , , T. UEDA-NAKAMURA، نويسنده , , Y. and Sakamoto، نويسنده , , M. and Noda، نويسنده , , N. and Watanabe، نويسنده , , T. and Shoji، نويسنده , , M. and Masuzaki، نويسنده , , S. and Morita، نويسنده , , S. and Goto، نويسنده , , M. and Torii، نويسنده , , Y. R. Takeuchi ، نويسنده , , N. and Shimpo، نويسنده , , F. and Nomura، نويسنده , , G. and Yokota، نويسنده , , M. and Kato، نويسنده , , A. and Zhao، نويسنده , , Y.، نويسنده ,
Abstract :
In the large helical device (LHD), the plasma duration time was extended up to 150 s by ion cyclotron range of frequencies (ICRF) heating. Time-integrated total input power reached 71 MJ. However, this discharge terminated due to radiation collapse accompanied by an increase of electron density. The temperature of the divertor plates and the intensity of Hα were locally increased in the same toroidal section, near the ICRF antenna. One of the possible causes of the increase of radiation power is an outgassing from the divertor plates that were heated by particles accelerated in the cyclotron resonance layer near the antenna. Another possible cause is the outgassing from the ICRF antenna itself due to a temperature increase of the ICRF antenna owing to high-energy particles, or the formation of an RF (radio frequency) sheath.
Keywords :
ICRF , LHD , Outgassing , RF , Steady state
