DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2013 EXPERIMENTAL CAMPAIGN Review | Direct submission with log-in | Request submission without log-in
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Title	371: Effect of icoil current on energy confinement in RMP ELM-suppressed discharges
Name:	Richard Groebner groebner@fusion.gat.com	Affiliation:	General Atomics
Research Area:	ELM Control	Presentation time:	Not requested
Co-Author(s):	--	ITPA Joint Experiment :	No
Description:	Determine how the plasma energy confinement varies with icoil current in discharges with ELMs suppressed via the application of RMP fields. Determine if confinement degradation with the application of these fields can be minimized by choice of icoil current.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Develop a robust ELM-suppressed discharge with RMP fields, applied with the icoil. Shot by shot, vary the icoil current and measure the H-factor and pedestal height for those discharges which remain ELM-suppressed.
Background:	ITER cannot tolerate large ELMs and the application of 3D fields via internal coils is planned on ITER as one technique to mitigate ELMs. This plan is strongly motivated by success on DIII-D in eliminating ELMs with the application of RMP fields from the icoil. However, ELM-suppressed H-modes typically show a reduction of energy confinement compared to that in the ELMing plasma prior to ELM suppression. This reduction of energy confinement is a concern to ITER scientists. The actual scaling of energy confinement with important control parameters, particularly the icoil current, is not well known. We need to determine the dependence of energy confinement on icoil current in RMP ELM suppressed regimes. It is plausible that for a current just above the threshold required to obtain ELM suppression that any reduction in energy confinement will be very small and acceptable. We need to find out if this is the case so that we can inform ITER.
Resource Requirements:	DIII-D tokamak, neutral beams, icoil
Diagnostic Requirements:	TS, CER
Analysis Requirements:	--
Other Requirements:	--