DIII-D RESEARCH OPPORTUNITIES FORUM FOR THE 2013 EXPERIMENTAL CAMPAIGN Review | Direct submission with log-in | Request submission without log-in
Print this page

Print this page
Title	104: Comparision of small-ELM regimes in DIII-D and NSTX
Name:	Aaron Sontag sontag@fusion.gat.com	Affiliation:	University of Wisconsin
Research Area:	ELM Control	Presentation time:	Requested
Co-Author(s):	R. Maingi, S. Gerhardt	ITPA Joint Experiment :	No
Description:	Compare edge regime characteristics in DIII-D during RMP mitigated ELMs to small-ELM regimes in NSTX. Filament structure, heat flux, collisionality and shape dependence will be examined. This is a JRT13 proposal	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	This proposal can be completed in piggy-back mode during RMP experiments that achieve ELM mitigation. Using shots with up/down (stellarator) symmetry allows analysis with stellarator equilibrium and stability tools, so data from ROF proposal #55 by Lazarus on ??RMP ELM suppression in DN plasmas? would be significantly helpful.
Background:	Understanding the factors that lead to small or suppressed ELMs allows development of ITER operational scenarios that have steady plasma edge conditions and predictable heat loading on PFCs. This proposal is to examine plasma edge characteristics in DIII-D during RMP mitigated ELMs and compare to small-ELM regimes in NSTX. Filament structure will be compared since some n=3 mitigated ELMs on DIII-D exhibit overlapping ELM structures, which is indicative of possible mixed modes, as is also observed in NSTX when n=3 fields are applied to ELMing discharges. Examine collisionality dependence of small-ELM regimes (can use existing data). Also look at dr-sep dependence of ELM characteristics. IR camera data will show the peak divertor heat flux variation with ELM size and frequency.
Resource Requirements:	Normal operations with RMP ELM suppression.
Diagnostic Requirements:	All profile diagnostics, BES and DBS to look at edge turbulence, IR camera for peak heat flux. SXR and upgraded 3D magnetics for filament mode structure.
Analysis Requirements:	Kinetic EFIT, VMEC
Other Requirements:	--