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	359: q95 scaling of the coupled turbulence/zonal flow during LH transition
Name:	Zheng Yan yanz@fusion.gat.com	Affiliation:	University of Wisconsin
Research Area:	L-H Transition	Presentation time:	Not requested
Co-Author(s):	George McKee, L. Schmitz, George Tynan, P. Diamond, Jose Boedo, Dimitry Rudakov	ITPA Joint Experiment :	No
Description:	The goal of this experiment is to investigate the q95 scaling of the coupled turbulence/zonal flow system before, during and after the L-H transition. Try to understand the L-H transition and the transition power threshold scaling physics.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	The main idea is to vary q95 at different momentum input (co, counter and balanced) to investigate zonal flow effects on LH transition. The beam power will be kept low to favor the Langmuir probe measurement of Reynolds stress at plasma edge. BES, UF-CHERS, DBS, CECE, etc will be used to measure plasma turbulence.
Background:	The existence of the geodestic acoustic mode (GAM) and the zero-mean-frequency (ZMF) zonal flow predicted to be generated by the plasma turbulence may relate to the mechanism for L- to H- mode transition [1]. It is shown that the zonal flow has strong q95 dependence. So far no q95 scan has been done. By completing these it will help understanding the underlying physics and the scaling of power threshold, which is a key issue for ITER.
Resource Requirements:	4 neutral beams
Diagnostic Requirements:	BES, CER, TS, DBS, CECE, PCI, Mid-plane probe with Reynolds stress head
Analysis Requirements:
Other Requirements: