RC Wolf, J Hobirk, GD Conway, O Gruber, A Gude, S Gunter, K Kirov, B Kurzan, F Leuterer, M Maraschek, PJ Mc Carthy, H Meister, GV Pereverzev, E Poli, F Ryter, W Treutterer, Q Yu

2001

September

Nuclear Fusion

Performance, heating and current drive scenarios of ASDEX Upgrade advanced tokamak discharges

Validated

WOS: 41 ()

INTERNAL TRANSPORT BARRIER REVERSED SHEAR DISCHARGES DIII-D TOKAMAK MHD PHENOMENA H-MODE MAGNETIC SHEAR ELECTRON JT-60U PLASMAS CONFINEMENT

41

1259

1271

Various approaches to high performance and steady state operation are presented. Strong neutral beam heating in the current ramp leads to internal transport barriers (ITBs) in conjunction with negative central magnetic shear. To avoid the destabilization of external kink modes this regime is limited to L mode edge operation with beta (N) < 1.7. In high poloidal , beta (p), discharges, full non-inductive current drive has been achieved transiently. At Greenwald density. values of beta (p) = 3.1, beta (N) = 2.8 and HITER89-P = 1.8 have been reached simultaneously. In plasmas with ITBs and L mode edge, additional ECRH and ECCD facilitates high core confinement with T-e approximate to T-a. Central ECCD has been applied in low density low current discharges. For ECCD in the co-current direction a current drive fraction of 82% is calculated. In the case of counter-ECCD, negative central shear with q(min) > 1 leads to the formation of an electron ITB.

BRISTOL

0029-5515