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	57: Develop a high performance L-mode plasma.
Name:	Edward Lazarus lazarus@fusion.gat.com	Affiliation:	Oak Ridge National Lab
Research Area:	General Physics	Presentation time:	Requested
Co-Author(s):	--	ITPA Joint Experiment :	No
Description:	Develop an L-mode plasma with a high performance core that sustains q0~2/3 and ql<2 (thus disruption-free). For details see my science meeting presentation of Nov. 16, 2012.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	There are 4 separate threads to be pursued and then combined. Each is non-trivial. (1)Attain operation with a m/n=1/1 boundary perturbation that sustains q0 at near 2/3. (2) Develop the capability to stabilize the external kink, as done on RFX. This will allow ql<2. (3) Investigate core parameters in such an L-mode case. Interchange stability and its consequences on electron and ion transport is of particular interest. In general, characterize confinement within a/2 vs plasma density, Ti/Te, beta_p_1, shape. (4) Investigate pumped limiter operation.
Background:	In recent work RFX demonstrated stabilization of the external kink and operated at ql~1.8. Recent VMEC calculations offer a plausible understanding of the TEXTOR q0 results (q0~2/3) as a consequence of relatively small n=1 error fields, suggesting this as a stable state of the tokamak (albeit with a helical core). Sawtooth experiments in oval shapes suggested dismal electron confinement, but excellent ion confinement. These might combine to produce a high performance core. It represents a plausible path towards an FNS. It should be considered as orthogonal to ITER, NOT as opposition to ITER.
Resource Requirements:	Varied. None are extraordinary. It may prove that power supply upgrades for the I-coils are needed. Without some initial efforts to stabilize the external kink, it is premature to speculate on this.
Diagnostic Requirements:	Nothing extraordinary.
Analysis Requirements:	To be developed.
Other Requirements:	A few weeks of run time per year for a few years. There is limited overlap with other proposed work.