Abstract Details
Abstracts
Author: Torrin A Bechtel
Requested Type: Poster
Submitted: 2017-03-16 12:41:50
Co-authors: C. C. Hegna, C. R. Sovinec
Contact Info:
University of Wisconsin - Madison
1500 Engineering Dr
Madison, WI 53706
United States
Abstract Text:
The finite beta properties of stellarator plasmas are studied with anisotropic conduction closure relations for heat flux using the nonlinear, extended MHD code NIMROD. The configuration under investigation is an l=2, M=10 torsatron with vacuum rotational transform near unity. Finite-beta plasmas are created using a volumetric heating source and temperature dependent resistivity. To reduce computation expenses, simulations only contain stellarator symmetric (integer multiples of M) toroidal modes. Extended MHD simulations are then performed to generate steady state solutions that represent 3D equilibrium conditions. With increasing beta, Shafranov shifts occur and associated break up of edge magnetic surfaces are observed. In this work we present results of independently varying the plasma heating and thermal anisotropy. Due to the presence of finite parallel heat conduction, pressure profiles can exist in regions of magnetic stochasticity. In particular, simulations show that the attained stored energy is a function of the magnitude of parallel heat conduction for a given heat source, indicating that equilibrium beta limits may be sensitive to anisotropic transport properties.*
*Research supported by US DOE under grant no. DE-FG02-99ER54546.
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