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	231: Stabilization of NTMs with ECCD
Name:	Akihiko Isayama isayama.akihiko@qst.go.jp	Affiliation:	QST
Research Area:	Stability & Disruption Avoidance	Presentation time:	Not requested
Co-Author(s):	R.J. La Haye, R. Buttery, M. Austin, G. Matsunaga, M. Takechi	ITPA Joint Experiment :	Yes
Description:	This proposal includes study of ECCD effect on NTM, which supplements previous experiments, taking into account the limited diagnostic capability in ITER. The experiments are related to the ITPA Joint Experiment MDC-8, "Current Drive Prevention/Stabilization of NTMs". In this proposal, the following experiments are included: (a) Modulation effect: identify the minimum EC wave power for complete stabilization both for modulated and unmodulated ECCD cases, (b) Phase effect: Investigate the stabilization effect (including destabilization for X-point ECCD) for different phase difference between NTM rotation and modulated EC wave power and (c) ECCD width effect: investigate the stabilization effect for different ECCD deposition width by changing the toroidal injection angle. This proposal is mainly focused on comparison of the behavior and structure of magnetic islands in DIII-D and JT-60U.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Experimental condition to obtain an m/n=2/1 NTM is based on the previous experiments in 2012. After the discharge scenario for obtaining 2/1NTM is established, ECCD parameters are changed with the same plasma parameters. Data for ECH (i.e. zero toroidal injection angle) and counter-ECCD are also taken for comparison.
Background:	Stabilization with modulated ECCD was successful, and some results have been reported from DIII-D, JT-60U and ASDEX-U. To supplement the results, in particular, to investigate the degradation of the stabilization effect due to deviation from the optimum condition, data on the above topics are taken. The result will have an impact on establishing the NTM stabilization scenario in ITER with limited diagnostic capability.
Resource Requirements:	neutral beams, ~6 gyrotrons, real-time system for NTM stabilization
Diagnostic Requirements:	magnetic probe, ECE (also oblique ECE if available), MSE, CER
Analysis Requirements:	REVIEW, NEWSPEC, TORAY
Other Requirements: