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Advancing the physics basis for quasi-helically symmetric stellarators

Published online by Cambridge University Press:  01 October 2020

A. Bader
Affiliation:
Department of Engineering Physics, University of Wisconsin-Madison, Madison 53706, USA
B. J. Faber
Affiliation:
Department of Engineering Physics, University of Wisconsin-Madison, Madison 53706, USA
J. C. Schmitt
Affiliation:
Department of Physics, Auburn University, Auburn 36849, USA
D. T. Anderson
Affiliation:
Department of Electrical Engineering, University of Wisconsin-Madison, Madison 53706, USA
M. Drevlak
Affiliation:
Max-Planck Institute for Plasma Physics, Greifswald 17491, Germany
J. M. Duff
Affiliation:
Department of Engineering Physics, University of Wisconsin-Madison, Madison 53706, USA
H. Frerichs
Affiliation:
Department of Engineering Physics, University of Wisconsin-Madison, Madison 53706, USA
C. C. Hegna
Affiliation:
Department of Engineering Physics, University of Wisconsin-Madison, Madison 53706, USA
T. G. Kruger
Affiliation:
Department of Electrical Engineering, University of Wisconsin-Madison, Madison 53706, USA
M. Landreman
Affiliation:
Institute for Research in Electronics and Applied Physics, University of Maryland, College Park 20742, USA
I. J. McKinney
Affiliation:
Department of Engineering Physics, University of Wisconsin-Madison, Madison 53706, USA
L. Singh
Affiliation:
Department of Electrical Engineering, University of Wisconsin-Madison, Madison 53706, USA
J. M. Schroeder
Affiliation:
Department of Physics, University of Wisconsin-Madison, Madison 53706, USA
P. W. Terry
Affiliation:
Department of Physics, University of Wisconsin-Madison, Madison 53706, USA
A. S. Ware
Affiliation:
Department of Physics and Astronomy, University of Montana, Missoula 59812, USA
Corresponding
E-mail address:

Abstract

A new optimized quasi-helically symmetric configuration is described that has the desirable properties of improved energetic particle confinement, reduced turbulent transport by three-dimensional shaping and non-resonant divertor capabilities. The configuration presented in this paper is explicitly optimized for quasi-helical symmetry, energetic particle confinement, neoclassical confinement and stability near the axis. Post optimization, the configuration was evaluated for its performance with regard to energetic particle transport, ideal magnetohydrodynamic stability at various values of plasma pressure and ion temperature gradient instability induced turbulent transport. The effects of discrete coils on various confinement figures of merit, including energetic particle confinement, are determined by generating single-filament coils for the configuration. Preliminary divertor analysis shows that coils can be created that do not interfere with expansion of the vessel volume near the regions of outgoing heat flux, thus demonstrating the possibility of operating a non-resonant divertor.

Type
Research Article
Copyright
Copyright © The Author(s), 2020. Published by Cambridge University Press

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