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Title	184: Comparision DIII-D and AUG high collisionality ELM response to 3D magnetic perturbations
Name:	Todd Evans evans@fusion.gat.com	Affiliation:	General Atomics
Research Area:	ELM Control	Presentation time:	Not requested
Co-Author(s):	W. Suttrop, et al., and ITPA PEP-23+25 Members	ITPA Joint Experiment :	Yes
Description:	The goal of this experiment is to reproduce ELM mitigation/suppression previously obtained in DIII-D with odd parity n=3 RMP fields and n=2 odd/even parity RMP fields in AUG at high density. A key question for understanding the interaction of RMP fileds with H-mode plasmas is whether the plasma response is dominated by collisionality or density when operating at high Greenwald fraction. This experiment will provide new information on the plasma response to n=3 field since we now have new diagnostic and operational capabilities compared to the original high Greenwald ELM suppression experiments done in DIII-D. In addition, comparisons with AUG results at high Greenwald fraction can provide important insights into the role of different RMP spetra on EML suppression physics and operational space.	ITER IO Urgent Research Task :	Yes
Experimental Approach/Plan:	In this experiment we will start by reproducing the shape and operating parameter used in DIII-D high Greenwald fraction ELM suppression discharge 115467 with n=3 odd parity RMP fields. Once ELM suppression is obtained we will carry out a density scan to see if we observe a density threshold similar to that seen in AUG with n=2 RMP fields. Next we will increase the I-coil current from 4.0 kA (used in 115467) to 6.3 kA to see if higher I-coil currents produce effects similar to those seen in low collisionality/density ELM suppression discharges. The final step involved evolving the discharge shape over several shot to better match the shape used in AUG ELM mitigation discharges.
Background:	Previous experiments done on both DIII-D and AUG have produce ELM suppression/mitigation at high Greenwald fraction. While some of the characteristics observed in these experiments are similar (e.g., little of no change in the pedestal profiles) others are significantly different (e.g., effects on toroidla rotation and the absence of a q95 resonance window in AUG). Understanding the mechanisms involved in these similarities and differences is important for determining wheather ElM suppression at high Greenwald fraction (and low collisionality) is viable in ITER. This experiment will contribute to work being done in the ITPA PEP-23 working group and is an urgent ITER issue.
Resource Requirements:	Detailed resource, diagnostic, analysis and other requirements are listed in D3DMP No.: 2011-01-05.http://fusion.gat.com/pubs-int/MiniP/review/2011-01-05.pdf
Diagnostic Requirements:
Analysis Requirements:
Other Requirements: