The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmasa)

• DOI: 10.1063/1.4921406
• Publication Date: 2015-05-26T17:02:12Z
• Authors: A. M. Garofalo; K. H. Burrell; D. Eldon; B. A. Grierson; J. M. Hanson; C. Holland; G. T. A. Huijsmans; F. Liu; A. Loarte; O. Meneghini; T. H. Osborne; C. Paz-Soldan; S. P. Smith; P. B. Snyder; W. M. Solomon; A. D. Turnbull; L. Zeng
• Keywords: Mode (computer interface)

For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER-like shape. QH-mode provides excellent even very low plasma rotation, while operating without edge localized modes (ELMs) with strong impurity transport via benign harmonic oscillation (EHO). By tailoring shape to improve stability, space has also been extended densities exceeding 80% Greenwald limit, overcoming long-standing low-density limit operation. In theory, density range over which encounters kink-peeling boundary widens as cross-section shaping is increased, thus increasing threshold. The results are agreement these predictions, nonlinear magnetohydrodynamic analysis reconstructed equilibria shows unstable n growing a saturated level, consistent theoretical picture EHO. Furthermore, high regime opened path new, previously predicted region parameter space, named "Super H-mode" because it characterized by pedestals that can be more than factor two above peeling-ballooning stability similar ELMing discharges same density.