Effect of plasma rotation on sawtooth stabilization by beam ions

Gorelenkov, N. N. ; Nave, M. F. F. ; Budny, R. ; Cheng, C. Z. ; Fu, G. Y. ; Hastie, J. ; Manickam, J. ; Park, W.

Princeton University. Plasma Physics Laboratory.

关键词: Sawtooth Oscillations;    Stabilization;    70 Plasma Physics And Fusion Technology;    Tftr Tokamak;    Beam Injection Heating;   

DOI  :  10.2172/757604
RP-ID  :  PPPL-3463
RP-ID  :  AC02-76CH03073
RP-ID  :  757604

美国|英语

来源: UNT Digital Library

【 摘 要 】

The sawtooth period in JET ELM-free H-Mode plasmas is increasing with Neutral Beam Injection (NBI) power. For injected power PNBI 12MW no large sawtooth crash is observed during the ELM-free period. However, as the edge stability is improved and external kink modes and ELMs are delayed, a possible sawtooth crash at a high plasma beta becomes a concern. In JET DT experiments, delaying sawteeth was found to be crucial in the quest for high fusion power. Fast particles are known to provide stabilizing effect on sawteeth, however, sawtooth stabilization by NBI ions is not clearly understood, since NBI ions are usually not ''fast'' enough to stabilize the m/n = 1/1 internal kink mode which is believed to cause the crash. In order to understand the observed sawteeth stabilization in tokamak experiments with NBI heating, the internal kink m/n = 1/1 mode stability of JET plasmas was modeled using the NOVA-K code, which is also benchmarked with the nonperturbative version of NOVA and the M3D code. Comparison of m/n = 1/1 mode stabilization by NBI ions in JET and TFTR and application of the nonlinear stabilization criteria is given.