Stability of Microturbulent Drift Modes during Internal Transport Barrier Formation in the Alcator C-Mod Radio Frequency Heated H-mode

Redi, M.H. ; Fiore, C.L. ; Dorland, W. ; Mikkelsen, D.R. ; Rewoldt, G. ; Bonoli, P.T. ; Ernst, D.R. ; Rice, J.E. ; Wukitch, S.J.

Princeton University. Plasma Physics Laboratory.

关键词: Drift Waves;    70 Plasma Physics And Fusion Technology;    Geometry;    Transport;    Stability;   

DOI  :  10.2172/820200
RP-ID  :  PPPL-3903
RP-ID  :  AC02-76CH03073
RP-ID  :  820200

美国|英语

来源: UNT Digital Library

【 摘 要 】

Recent H-mode experiments on Alcator C-Mod [I.H. Hutchinson, et al., Phys. Plasmas 1 (1994) 1511] which exhibit an internal transport barrier (ITB), have been examined with flux tube geometry gyrokinetic simulations, using the massively parallel code GS2 [M. Kotschenreuther, G. Rewoldt, and W.M. Tang, Comput. Phys. Commun. 88 (1995) 128]. The simulations support the picture of ion/electron temperature gradient (ITG/ETG) microturbulence driving high xi/ xe and that suppressed ITG causes reduced particle transport and improved ci on C-Mod. Nonlinear calculations for C-Mod confirm initial linear simulations, which predicted ITG stability in the barrier region just before ITB formation, without invoking E x B shear suppression of turbulence. Nonlinear fluxes are compared to experiment, which both show low heat transport in the ITB and higher transport within and outside of the barrier region.