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(EX4/4) Performance, Heating, and Current Drive Scenarios of ASDEX Upgrade Advanced Tokamak Discharges

R. C. Wolf¹⁾, J. Hobirk¹⁾, G. Conway¹⁾, O. Gruber¹⁾, A. Gude¹⁾, S. Günter¹⁾, K. Kirov¹⁾, B. Kurzan¹⁾, M. Maraschek¹⁾, P. McCarthy²⁾, H. Meister¹⁾, F. Leuterer¹⁾, G. V. Pereverzev¹⁾, E. Poli¹⁾, F. Ryter¹⁾ and the ASDEX Upgrade Team
 
¹⁾ Max-Planck Insitut für Plasmaphysik, EURATOM-Association, D-85748 Garching
²⁾ Physics Department, University College Cork, Association Euratom-DCU, Cork Ireland

Abstract.  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. In high $\beta_{p}^{}$ discharges full non-inductive current drive has been achieved transiently. At Greenwald density values of $\beta_{p}^{}$ = 3.1, $\beta_{N}^{}$ = 2.8, and H_{ITER89 - P} = 1.8 have been reached simultaneously. In plasmas with ITBs and L-mode edge additional electron cyclotron resonance heating (ECRH) and current drive (ECCD) facilitates high core confinement with T_e $\approx$ T_i. Central ECCD has been applied in low density, low current discharge. For ECCD in co-current direction a current drive fraction of 82% is calculated. In case of counter-ECCD negative central shear with q_min > 1 leads to the formation of an electron ITB.

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