Dependence of the L-H transition on X-point geometry and divertor recycling on NSTX

被引：23

作者：

Battaglia, D. J. ^{[1
]}

Chang, C. S. ^{[1
]}

Kaye, S. M. ^{[1
]}

Kim, K. ^{[2
]}

Ku, S. ^{[1
]}

Maingi, R. ^{[3
]}

Bell, R. E. ^{[1
]}

Diallo, A. ^{[1
]}

Gerhardt, S. ^{[1
]}

LeBlanc, B. P. ^{[1
]}

Menard, J. ^{[1
]}

Podesta, M. ^{[1
]}

机构：

[1] Princeton Plasma Phys Lab, Princeton, NJ 08543 USA

[2] Korea Adv Inst Sci & Technol, Taejon 305701, South Korea

[3] Oak Ridge Natl Lab, Oak Ridge, TN USA

来源：

NUCLEAR FUSION | 2013年 / 53卷 / 11期

关键词：

TOKAMAK; PLASMA;

D O I：

10.1088/0029-5515/53/11/113032

中图分类号：

O35 [流体力学]; O53 [等离子体物理学];

学科分类号：

070204 ; 080103 ; 080704 ;

摘要：

The edge electron (T-e) and ion temperature (T-i) at the time of the L-H transition increase when the X-point radius (R-X) is reduced to a high-triangularity shape while maintaining constant edge density. Consequently the L-H power threshold (P-LH) is larger for the high-triangularity shape. This supports the prediction that a single-particle loss hole, whose properties are strongly linked to R-X and T-i, influences the edge radial electric field (E-r) and E-r x B flow-shearing rate available for turbulence suppression. Simulations using XGC0, a full-f drift-kinetic neoclassical code, indicate that maintaining a constant E-r x B flow-shearing rate does require a larger heat flux and edge T-i as R-X decreases. NSTX also observes a decrease in P-LH when the divertor recycling is decreased using lithium coatings. However, the edge T-e and T-i at the L-H transition appear independent of the divertor recycling for a constant shape. XGC0 calculations demonstrate that more heat flux is needed to maintain the edge Ti and the E-r x B flow-shearing rate as the contribution of divertor recycling to the overall neutral fuelling rate increases.

引用

页数：8

共 32 条

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