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chrishansen_epr_2014_pre.pdf2014-08-14 09:04:15Chris Hansen

THE PSI-TET FRAMEWORK FOR 3D MHD: APPLICATION TO INJECTOR COUPLING AND CURRENT DRIVE IN HIT-SI

Author: Chris J Hansen
Requested Type: Consider for Invited
Submitted: 2014-05-30 13:16:19

Co-authors: C. Akcay, K. Morgan, B. Victor, G. Marklin, T. Jarboe

Contact Info:
University of Washington
University of Washington, Box
Seattle, Wa   98195
USA

Abstract Text:
A new 3D non-linear Hall MHD code has been developed using the PSI-TET framework, which is capable of modeling the full HIT-SI geometry with consistent boundary conditions for the insulator coated flux conserver. Using this code, simulations of the HIT-SI experiment have been performed that capture plasma dynamics in the injector regions for the first time. Results will be presented from simulations using a simplified Hall MHD model, where density and temperature are assumed to be uniform and constant. Field reversal and associated reconnection processes in the injectors, produced by AC operation of the HIT-SI circuits, are observed to be asymmetric within a single injector, relative to the two injector mouths, and between injectors, where the fluctuation amplitude associated with reversal is larger in one injector than the other. Comparison to experimental data using the simplified model shows areas of improved agreement in magnetic fluctuations and global mode structures over previous NIMROD simulations that modeled injector fields through boundary conditions on the flux conserver. Good overall agreement has been achieved with both PSI-TET and NIMROD using the simplified Hall MHD model when the injectors are driven with a frequency of 14.5 kHz, however detailed comparison and deviation at higher frequencies indicates additional physics may be required. Experimental observations at higher injector drive frequencies indicate significant pressure affects are important, which are neglected by the simplified model. Simulations are now being conducted with density and temperature evolution using PSI-TET and NIMROD to address this effect and progress on this work will also be presented. Work supported by DOE.

Characterization: 2.0

Comments:
If not chosen for a talk please group with other HIT-SI posters.

Workshop on Exploratory Topics in Plasma and Fusion Research (EPR) and US-Japan Compact Torus (CT) Workshop
August 5-8, 2014
Madison, Wisconsin

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