Transition dynamics and confinement scaling in COMPASS-D H mode plasmas

被引:15
作者
Fielding, SJ [1 ]
Carolan, PG [1 ]
Connor, JW [1 ]
Conway, NJ [1 ]
Field, AR [1 ]
Helander, P [1 ]
Igitkhanov, Y [1 ]
Lloyd, B [1 ]
Meyer, H [1 ]
Morris, AW [1 ]
Pogutse, O [1 ]
Valovic, M [1 ]
Wilson, HR [1 ]
机构
[1] UKAEA Euratom Fus Assoc, Abingdon, Oxon, England
关键词
D O I
10.1088/0029-5515/41/7/312
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
An experimental analysis is discussed of different phases of ECRH II mode discharges on COMPASS-D, from L-H transition triggering to steady state. Comprehensive high resolution measurements in the transport barrier region have enabled significant progress to be made in assessing H mode transition models, together with additional experiments aimed at resolving controlling trigger mechanisms. The application of four possible transition models to the data indicates that all demonstrate limiting or critical parameter values at the transition. One of them, based on Alfven drift wave turbulence suppression, exhibits precursor behaviour in the stability regime diagram and predicts the density and magnetic field dependences of the H mode power threshold observed on COMPASS-D. Analysis of the evolution of the local radial electric field and its shear indicates that significant shear only develops after the L-H transition. Stationary ELMy H modes are achieved at. high rho* with good confinement, and dimensionless scaling over a range of nu* has been carried out, providing valuable confinement data in a regime where heat is deposited primarily to the electrons.
引用
收藏
页码:909 / 917
页数:9
相关论文
共 20 条
[1]   Transition physics and scaling overview [J].
Carlstrom, TN .
PLASMA PHYSICS AND CONTROLLED FUSION, 1996, 38 (08) :1149-1160
[2]  
CAROLAN PG, 1995, P 22 EPS C CONTR C 2, V19, P133
[3]   Comparison of theoretical models for scrape-off layer widths with data from COMPASS-D, JET and Alcator C-Mod [J].
Connor, JW ;
Counsell, GF ;
Erents, SK ;
Fielding, SJ ;
LaBombard, B ;
Morel, K .
NUCLEAR FUSION, 1999, 39 (02) :169-188
[4]   Magnetohydrodynamic stability of tokamak edge plasmas [J].
Connor, JW ;
Hastie, RJ ;
Wilson, HR ;
Miller, RL .
PHYSICS OF PLASMAS, 1998, 5 (07) :2687-2700
[5]   Optimized instrumentation for edge Te and ne measurements on COMPASS-D tokamak from He I line intensity ratios [J].
Field, AR ;
Carolan, PG ;
Conway, NJ ;
O'Mullane, MG .
REVIEW OF SCIENTIFIC INSTRUMENTS, 1999, 70 (01) :355-358
[6]   The H-mode in COMPASS-D [J].
Fielding, SJ ;
Ashall, JD ;
Carolan, PG ;
Colton, A ;
Gates, D ;
Hugill, J ;
Morris, AW ;
Valovic, M .
PLASMA PHYSICS AND CONTROLLED FUSION, 1996, 38 (08) :1091-1102
[7]   The influence of MHD instabilities on the COMPASS-D H-mode threshold [J].
Fielding, SJ ;
Field, AR ;
Valovic, M ;
Wilson, HR ;
Carolan, PG ;
Connor, JW ;
Conway, NJ ;
Dowling, J ;
Lloyd, B ;
Morris, AW .
PLASMA PHYSICS AND CONTROLLED FUSION, 2000, 42 :A191-A197
[8]  
FIELDING SJ, 1998, CONTROLLED FUSION C, V22, pB92
[9]  
Fülöp T, 1999, PHYS PLASMAS, V6, P3066, DOI 10.1063/1.873593
[10]   Bifurcated neoclassical particle transport [J].
Helander, P .
PHYSICS OF PLASMAS, 1998, 5 (11) :3999-4004