High-beta discharges in the DIII-D tokamak
- 1 June 1990
- journal article
- Published by AIP Publishing in Physics of Fluids B: Plasma Physics
- Vol. 2 (6) , 1280-1286
- https://doi.org/10.1063/1.859543
Abstract
Low‐q (q95q95≊5, values of βT/(I/aB) as high as 5 have been obtained. These discharges are shown to be at or below the stability limit to the value of beta for infinite‐n, ideal ballooning modes. The discharges are significantly below the beta limit for ideal,low toroidal mode number kink modes. The kink mode beta limit is shown to be strongly dependent on the radial profiles of plasma pressure and current. The theoretical beta limit in DIII‐D is shown to be in the range βT/(I/aB)=4 –5 depending on the value of I/aB, and this is consistent with the experiment. High‐beta discharges have been operated with ion temperature up to 17 keV. Steady‐state, high‐beta, low‐q operation is demonstrated by a discharge with I/aB=2.6, q95=2.7, in which βT>7% is maintained for 1.5 sec.Keywords
This publication has 9 references indexed in Scilit:
- MHD instabilities near theβlimit in the doublet III-D tokamakPhysical Review Letters, 1989
- Achievement of reactor-relevantβin low-qdivertor discharges in the doublet III-D tokamakPhysical Review Letters, 1989
- Energy confinement properties of H-mode discharges in the DIII-D tokamakNuclear Fusion, 1989
- Study of Giant Edge-Localized Modes in DIII-D and Comparison with Ballooning TheoryPhysical Review Letters, 1988
- Resistive ballooning modes in high-beta tokamaksNuclear Fusion, 1985
- Big Dee - A Flexible Facility Operating Near Breakeven ConditionsFusion Technology, 1985
- MHD-Limits to Plasma ConfinementPlasma Physics and Controlled Fusion, 1984
- Study of High-Beta Magnetohydrodynamic Modes and Fast-Ion Losses in PDXPhysical Review Letters, 1983
- GATO: An MHD stability code for axisymmetric plasmas with internal separatricesComputer Physics Communications, 1981