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	360: density scaling and X-point position scan of LH transition power threshold
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 physics behind the density scaling of the L-H transition power threshold, especially the density minimal for the power threshold.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	The main idea is to vary electron density at different X-point position in balanced beam injection plasma. Start with the plasma condition and shape used in the last L-H expt. in 2012 campaign lowest density, then reduce density more to try to find the region where L-H power threshold increases with decreasing density. If no density minimal can be found in that condition, then adjust X-point position relative to the pumping for another density scan. 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:	In 2012 campaign L-H expt. no density minimal of the L-H power threshold had been observed. This contrasts to the observations made years before. The X-point position could be a factor for this difference.
Resource Requirements:	4 neutral beams
Diagnostic Requirements:	: BES, CER, TS, DBS, CECE, PCI, Mid-plane probe with Reynolds stress head
Analysis Requirements:
Other Requirements: