Transport-driven scrape-off layer flows and the x-point dependence of the L-H power threshold in Alcator C-Mod -: art. no. 056111

被引：90

作者：

LaBombard, B ^{[1
]}

Rice, JE ^{[1
]}

Hubbard, AE ^{[1
]}

Hughes, JW ^{[1
]}

Greenwald, M ^{[1
]}

Granetz, RS ^{[1
]}

Irby, JH ^{[1
]}

Lin, Y ^{[1
]}

Lipschultz, B ^{[1
]}

Marmar, ES ^{[1
]}

Marr, K ^{[1
]}

Mossessian, D ^{[1
]}

Parker, R ^{[1
]}

Rowan, W ^{[1
]}

Smick, N ^{[1
]}

Snipes, JA ^{[1
]}

Terry, JL ^{[1
]}

Wolfe, SM ^{[1
]}

Wukitch, SJ ^{[1
]}

机构：

[1] MIT, Plasma Sci & Fus Ctr, Cambridge, MA 02139 USA

来源：

PHYSICS OF PLASMAS | 2005年 / 12卷 / 05期

关键词：

D O I：

10.1063/1.1876294

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：

Factor of similar to 2 higher power thresholds for low- to high-confinement mode transitions (L-H) with unfavorable x-point topologies in Alcator C-Mod [Phys. Plasmas 1, 1511 (1994)] are linked to flow boundary conditions imposed by the scrape-off layer (SOL). Ballooning-like transport drives flow along magnetic field lines from low- to high-field regions with toroidal direction dependent on upper/lower x-point balance; the toroidal rotation of the confined plasma responds, exhibiting a strong counter-current rotation when Bx del B points away from the x point. Increased auxiliary heating power (rf, no momentum input) leads to an L-H transition at approximately twice the edge electron pressure gradient when Bx del B points away. As gradients rise prior to the transition, toroidal rotation ramps toward the co-current direction; the H mode is seen when the counter-current rotation imposed by the SOL flow becomes compensated. Remarkably, L-H thresholds in lower-limited discharges are identical to lower x-point discharges; SOL flows are also found similar, suggesting a connection. (c) 2005 American Institute of Physics.

引用

页数：10

共 36 条

[1] 13C transport studies in L-mode divertor plasmas on DIII-D [J].