@inproceedings{542a0b117dd543d8b1fdfee64ddc16bd,
title = "Sustained high beta plasmas with negative central shear in DIII-D",
abstract = "Simultaneous ramping of the plasma current and toroidal field, and application of early neutral beam heating in DIII-D have produced current-hole type discharges sustained for ≈2s at high values of normalized pressure (βN≈ 4) and safety factor (qmin ≈ 2). The combination of internal transport barrier and negative central magnetic shear results in high energy confinement (H89 > 2.5) and good bootstrap current alignment (fBS ≈ 60%). Previously, stability limits in plasmas with core transport barriers have been observed at moderate values of βN(<3) because of characteristically high pressure-peaking. A noninductive current fraction of ≈90% has been observed at plasma β ≈ 5% in these DIII-D experiments. Stability modeling shows the possibility for operation up to β ≈ 6%, suggesting a possible path to high fusion performance, steady-state tokamak scenarios with a large fraction of bootstrap current.",
author = "Garofalo, {A. M.} and Doyle, {E. J.} and Greenfield, {C. M.} and Hyatt, {A. W.} and Jackson, {G. L.} and Jayakumar, {R. J.} and Kessel, {C. E.} and Kim, {J. Y.} and {La Haye}, {R. J.} and M. Murakami and M. Okabayashi and H. Reimerdes and Scoville, {J. T.} and John, {H. E.St} and Strait, {E. J.}",
year = "2005",
language = "English",
isbn = "9781622763320",
series = "32nd EPS Conference on Plasma Physics 2005, EPS 2005, Held with the 8th International Workshop on Fast Ignition of Fusion Targets - Europhysics Conference Abstracts",
pages = "145--148",
booktitle = "32nd EPS Conference on Plasma Physics 2005, EPS 2005, Held with the 8th International Workshop on Fast Ignition of Fusion Targets - Europhysics Conference Abstracts",
note = "32nd European Physical Society Conference on Plasma Physics and Controlled Fusion combined with the 8th International Workshop on Fast Ignition of Fusion Targets ; Conference date: 27-06-2005 Through 01-07-2005",
}