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	308: RMP (Resonant Magnetic Perturbation) code validation via UCLA 288 GHz polarimeter
Name:	Jie Zhang xyzhangj@physics.ucla.edu	Affiliation:	University of California, Los Angeles
Research Area:	ELM Control	Presentation time:	Not requested
Co-Author(s):	Tony Peebles, Troy Carter, Neal Crocker, Edward Doyle, Terry Rhodes, Todd Evans, Guiding Wang, Mike Van Zeeland, Lei Zeng	ITPA Joint Experiment :	No
Description:	The purpose of this experiment is to validate the code predictions, e.g., TRIP3D and M3D-C1, for plasma response to RMP. The TRIP3D calculates the magnetic field produced by I-coils in vacuum, while M3D-C1 includes other plasma response, predicting the magnetic and density perturbations. The magnetic perturbations predicted by these two codes, however, are quite different. The recently commissioned UCLA 288 GHz polarimeter can provide an experimental measurement of the internal magnetic field perturbation.	ITER IO Urgent Research Task :	No
Experimental Approach/Plan:	Low electron density (ne < 4E19 m-3) discharges are preferred for optimal performance of the polarimeter. The plasma center is positioned at +7.5 cm, the height of horizontal polarimeter diagnostic beam, to reduce refraction due to density gradient transverse the beam. The I-coils are operated with either n=2 or n=1 configuration. Operational details, for instance, plasma shape, the I-coil frequency, magnitude, and on/off period, etc., are under active discussion. Target shots will be developed during the startup of the campaign. Due to the line-integral nature of the polarimetry measurements, density perturbation measurements should simultaneously be acquired with profile reflectometer, BES, Lithium beam (when applicable). A synthetic diagnostic code, which has been developed to calculate the polarimeter response with inputs of density and magnetic profiles, will be utilized to assist measurement interpretation. Toroidal field will be scanned, i.e. BT = 0.75 T, 1.5 T, and 2.0 T. This will vary the contribution from the Cotton-Mouton effects to the polarimeter measurements, and hence the density perturbations.
Background:
Resource Requirements:	NBI for MSE, CER and BES diagnostics
Diagnostic Requirements:
Analysis Requirements:	EFITs, TRIP3D, M3D-C1
Other Requirements: