Abstract Details

Presentation:submitted:by:
poster.pdf2006-02-26 17:26:20Max Wyman

Higher ion temperature and higher density plasmas with improved confinement in MST

Author: Max D Wyman
Submitted: 2006-01-17 14:22:17

Co-authors: MST Team (UW-Madison), ORNL Pellet Fueling Group

Contact Info:
University of Wisconsin
1150 University Ave
Madison, WI   53703
USA

Abstract Text:
MST plasmas with reduced fluctuations and improved confinement are achieved with auxiliary inductive current drive. In such plasmas, the electron temperature (Te) increases as much as three fold to well in excess of 1 keV, but the ion temperature (Ti) usually changes very little, remaining at a few hundred eV. Now, for the first time in the RFP, a Ti sustained in excess of 1 keV has been observed in these plasmas. This is apparently the result of ion heating generated by magnetic reconnection events occurring shortly before the improved confinement is triggered and appears to be linked to a recent increase in MST's toroidal current capability (up to 0.6 MA). At low toroidal current, the unchanging Ti during improved confinement is due in part to a relatively low density (∼ 10^19 m^-3), which leads to slow electron-ion energy transfer but this has been necessary to prevent the onset of confinement-degrading fluctuations. Since the rate of electron-ion energy transfer increases with density, injection of deuterium pellets has been attempted, and we have increased the density in these plasmas by about 70% while still effecting fluctuation reduction. Work supported by USDOE.

Characterization: A5

Comments:

The University of Texas at Austin

Innovative Confinement Concepts Workshop
February 13-16, 2006
Austin, Texas

ICC 2006 UT logo