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epr_abstract.pdf2014-05-29 12:03:53Adrian Akerson

Investigation of Perpendicular and Parallel Transport in the Edge of HSX Stellarator and Comparisons with EMC3- EIRENE

Author: Adrian R. Akerson
Requested Type: Poster Only
Submitted: 2014-05-29 12:08:06

Co-authors: A. Bader, O. Schmitz, F. S. B. Anderson, C. C. Hegna, D. T. Anderson

Contact Info:
University of Wisconsin
1415 Engineering Dr.
Madison, WI   53706

Abstract Text:
The presence of edge magnetic islands is intrinsic to all stellarators and plays a prominent role in all aspects of edge physics. In this work, temperature, density, parallel ion flows, and floating potential profiles in the HSX stellarator edge are presented. Measurements are made with a Langmuir probe equipped with a flapping mechanism, allowing for a 2 dimensional map of plasma parameters in an edge region that includes magnetic islands. Comparisons of these measurements to simulations [1] using the EMC3-EIRENE [2] 3-D plasma fluid and kinetic neutral gas transport model are made. Qualitatively, both simulation and experiment show consistent density and temperature profiles within the LCFS. However, in the edge region, discrepancies in temperature, density, and parallel flow are present, and are the subject of investigation. Prominent features in the electrostatic potential are measured, particularly within the separatricies of magnetic islands. These electrostatic potentials and the resulting E x B flows are not present in the EMC3-EIRENE modeling and may contribute to discrepancies between experiment and simulations. Future work will concentrate on understanding the origin of these potential structures and their impact on the edge plasma properties.

This work supported by US DOE Grant DE-FG02-93ER54222

[1] A. Bader et al. “Simulations of edge configurations in quasi-helically symmetric geometry using EMC3-EIRENE.” Nucl. Fusion 53 (2013)

[2] Y. Feng et al. “3D edge modeling and island divertor physics.” Contrb. Plasma Physics. 44 (2004).

Characterization: 3.0


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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