Hybrid H-mode scenario with nitrogen seeding and type III ELMs in JET

作者：Corre Y^*; Joffrin E; Monier Garbet P; Andrew Y; Arnoux G; Beurskens M; Brezinsek S; Brix M; Buttery R; Coffey I; Crombe K; de La Luna E; Felton R; Giroud C; Hacquin S; Hobirk J; Huber A; Imbeaux F; Jachmich S; Kempenaars M; Litaudon X; Leggate H; Loarer T; Maddison G; Rachlew E; Rapp J; Sauter O; Savchkov A; Telesca G; Widdowson A; Zastrow K D; Zimmermann O

来源：Plasma Physics and Controlled Fusion, 2008, 50(11): 115012.

DOI：10.1088/0741-3335/50/11/115012

The performance of the 'hybrid' H-mode regime (long pulse operation with high neutron fluency) has been extensively investigated in JET during the 2005-2007 experimental campaign up to normalized pressure beta(N) = 3, toroidal magnetic field B(t) = 1.7T, with type I ELMs plasma edge conditions. The optimized external current drive sources, self-generated non-inductive bootstrap current and plasma core stability properties provide a good prospect of achieving a high fusion gain at reduced plasma current for long durations in ITER.
One of the remaining issues is the erosion of the divertor target plates associated with the type I ELM regime. A possible solution could be to operate with a plasma edge in the type III ELM regime (reduced transient and stationary heat loads) obtained with impurity seeding. An integrated hybrid type III ELM regime with a normalized pressure beta(N) = 2.6 (PNBI similar to 20-22 MW) and a thermal confinement factor of H(98)* 98(y, 2) similar to 0.83 has been recently successfully developed on JET with nitrogen seeding. This scenario shows good plasma edge condition (compatible with the future ITER-like wall on JET) and moderate MHD activity. In this paper, we report on the experimental development of the scenario (with plasma current I(p) = 1.7MA and magnetic field B(t) = 1.7T) and the trade-off between heat load reduction at the target plates and global confinement due to nitrogen seeding and type III ELM working conditions.

• 出版日期2008-11
• 单位中国地震局