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Title	8: Compare Mach probe and CER measurements of intrinsic rotation profile of main ions in helium plasma
Name:	Keith Burrell Burrell@fusion.gat.com	Affiliation:	General Atomics
Research Area:	Plasma Rotation	Presentation time:	Not requested
Co-Author(s):	J. Boedo, J.S. DeGrassie, W.M. Solomon, B.A. Grierson	ITPA Joint Experiment :	No
Description:	The goal of this work is to measure the edge main ion toroidal rotation profile in helium plasmas with the Mach probe with the CER system and then compare them. The goal is to verify that we see the same edge rotation structure on both diagnostics, including the localized peak seen previously (see background). The data will be used to compare with XGC0 calculations to see if we can achieve a physics understanding of this work.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Utilize low power ECH H-mode plasmas like 140420-437 as the basic target. Measure edge main ion profile with Mach probe and CER at various times both before and after the L to H transition. Since the Mach probe plunges at one or two times and since the beam blip for CER seriously affects the rotation, multiple shot will be required to obtain a complete time history. Obtain complete edge profile data needed for the XGC0 modelling.
Background:	Experimental measurements of the edge main ion rotation profile in ECH H-modes (shot range 141444-141487) using the reciprocating Mach probe showed a localized peak in the deuteron rotation profile with the top of the peak on the separatrix. Data mining of helium H-mode plasmas from several years ago (shots 140420-437) demonstrated a similar structure in the main ion rotation. From the standpoint of angular momentum transport, this localized peak is quite surprising, since it is inconsistent with simple transport models. The structure may be a consequence of ion orbits crossing the separatrix; such effects have been predicted by the XGC0 code, although the spatial structure doesnot exactly match the experiment.
Resource Requirements:	Helium plasmas with ECH
Diagnostic Requirements:	Mach probe. Standard profile diagnostics including CER.
Analysis Requirements:	--
Other Requirements:	--