E J Doyle et al 2006 Plasma Phys. Control. Fusion 48 B39 doi:10.1088/0741-3335/48/12B/S04
E J Doyle1, A M Garofalo2, C M Greenfield3, S M Kaye4, J E Menard4, M Murakami5, S A Sabbagh2, M E Austin6, R E Bell4, K H Burrell3, J R Ferron3, D A Gates4, R J Groebner3, A W Hyatt3, R J Jayakumar7, J E Kinsey8, B P LeBlanc4, T C Luce3, G R McKee9, M Okabayashi4, Y-K M Peng5, C C Petty3, P A Politzer3, T L Rhodes1, M R Wade3, R E Waltz3, the DIII-D and NSTX Research Teams
Show affiliationsAdvanced tokamak (AT) research seeks to develop steady-state operating scenarios for ITER and other future devices from a demonstrated scientific basis. Normalized target parameters for steady-state operation on ITER are 100% non-inductive current operation with a bootstrap current fraction fBS ≥ 60%, q95 ~ 4–5 and
. Progress in realizing such plasmas is considered in terms of the development of plasma control capabilities and scientific understanding, leading to improved AT performance. NSTX has demonstrated active resistive wall mode stabilization with low, ITER-relevant, rotation rates below the critical value required for passive stabilization. On DIII-D, experimental observations and GYRO simulations indicate that ion internal transport barrier (ITB) formation at rational-q surfaces is due to equilibrium zonal flows generating high local E × B shear levels. In addition, stability modelling for DIII-D indicates a path to operation at βN ≥ 4 with qmin ≥ 2, using broad, hollow current profiles to increase the ideal wall stability limit. Both NSTX and DIII-D have optimized plasma performance and expanded AT operational limits. NSTX now has long-pulse, high performance discharges meeting the normalized targets for an spherical torus-based component test facility. DIII-D has developed sustained discharges combining high beta and ITBs, with performance approaching levels required for AT reactor concepts, e.g. βN = 4, H89 = 2.5, with fBS > 60%. Most importantly, DIII-D has developed ITER steady-state demonstration discharges, simultaneously meeting the targets for steady-state Q ≥ 5 operation on ITER set out above, substantially increasing confidence in ITER meeting its steady-state performance objective.
52.55.Fa Tokamaks, spherical tokamaks
Issue 12B (December 2006)
Received 23 June 2006
Published 8 November 2006
E J Doyle et al 2006 Plasma Phys. Control. Fusion 48 B39
Henry C. Ferguson et al 2004 ApJ 600 L107
Michael R. Corbin and William D. Vacca 2002 ApJ 581 1039
K. Doubrovinski and K. Kruse 2008 EPL 83 18003
Andrew H Cannon et al 2005 J. Micromech. Microeng. 15 2172
J. N. Wilking and T. G. Mason 2008 EPL 81 58005
Ann Merchant Boesgaard and Megan C. Novicki 2006 ApJ 641 1122
W A Clarkson 2001 J. Phys. D: Appl. Phys. 34 2381
M. Tumminello et al 2007 EPL 78 30006
Harry I. Ringermacher and Lawrence R. Mead 2009 The Astronomical Journal 137 4716