L to H mode transition: on the role of Zeff

被引：44

作者：

Bourdelle, C. ^{[1
]}

Maggi, C. F. ^{[2
]}

Chone, L. ^{[1
,3
]}

Beyer, P. ^{[3
]}

Citrin, J. ^{[1
,4
]}

Fedorczak, N. ^{[1
]}

Garbet, X. ^{[1
]}

Loarte, A. ^{[5
]}

Millitello, F. ^{[6
]}

Romanelli, M. ^{[6
]}

Sarazin, Y. ^{[1
]}

机构：

[1] CEA, IRFM, F-13108 St Paul Les Durance, France

[2] EURATOM, Max Planck Inst Plasmaphys, Garching, Germany

[3] Univ Aix Marseille, CNRS, PIIM, UMR 7345, F-13397 Marseille 20, France

[4] EURATOM, Dutch Inst Fundamental Energy Res, FOM Inst DIFFER, Nieuwegein, Netherlands

[5] ITER Org, F-13115 St Paul Les Durance, France

[6] Culham Ctr Fus Energy, Abingdon, Oxon, England

来源：

NUCLEAR FUSION | 2014年 / 54卷 / 02期

关键词：

turbulence; gyrokinetic; tokamak; plasma; H mode; DIVERTOR GEOMETRY; PARTICLE-TRANSPORT; IMPURITY BEHAVIOR; TOKAMAK PLASMAS; VARIED GEOMETRY; JET DIVERTORS; TURBULENCE; THRESHOLD; DISCHARGES; POWER;

D O I：

10.1088/0029-5515/54/2/022001

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：

In this paper, the nature of the primary instability present in the pedestal forming region prior to the transition into H mode is analysed using a gyrokinetic code on JET-ILWprofiles. The linear analysis shows that the primary instability is of resistive nature, and can therefore be stabilized by increased temperature, hence power. The unstable modes are identified as being resistive ballooning modes. Their growth rates decrease for temperatures increasing towards the experimentally measured temperature at the L-H transition. The growth rates are larger for lower effective charge Z(eff). This dependence is shown to be in qualitative agreement with recent and past experimental observations of reduced Z(eff) associated with lower L-H power thresholds.

引用

页数：5

共 40 条

[1] JET divertor geometry and plasma shape effects on the L-H transition threshold [J].