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Title: Radial electric field and ion parallel flow in the quasi-symmetric and Mirror configurations of HSX

Abstract

In this paper, the radial electric field and the ion mean parallel flow are obtained in the helically symmetric experiment stellarator from toroidal flow measurements of C+6 ion at two locations on a flux surface, using the Pfirsch–Schlüter effect. Results from the standard quasi-helically symmetric magnetic configuration are compared with those from the Mirror configuration where the quasi-symmetry is deliberately degraded using auxiliary coils. For similar injected power, the quasi-symmetric configuration is observed to have significantly lower flows while the experimental observations from the Mirror geometry are in better agreement with neoclassical calculations. Finally, indications are that the radial electric field near the core of the quasi-symmetric configuration may be governed by non-neoclassical processes.

Authors:
ORCiD logo [1];  [1];  [1];  [2];  [1]
  1. Univ. of Wisconsin, Madison, WI (United States). HSX Plasma Lab. Dept. of Electrical and Computer Engineering
  2. Univ. of Wisconsin, Madison, WI (United States). HSX Plasma Lab. Dept. of Electrical and Computer Engineering; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin, Madison, WI (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES)
OSTI Identifier:
1432157
Grant/Contract Number:  
AC05-00OR22725; FG02-93ER54222
Resource Type:
Accepted Manuscript
Journal Name:
Plasma Physics and Controlled Fusion
Additional Journal Information:
Journal Volume: 60; Journal Issue: 5; Journal ID: ISSN 0741-3335
Publisher:
IOP Science
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Kumar, S. T. A., Dobbins, T. J., Talmadge, J. N., Wilcox, R. S., and Anderson, D. T. Radial electric field and ion parallel flow in the quasi-symmetric and Mirror configurations of HSX. United States: N. p., 2018. Web. doi:10.1088/1361-6587/aab4c7.
Kumar, S. T. A., Dobbins, T. J., Talmadge, J. N., Wilcox, R. S., & Anderson, D. T. Radial electric field and ion parallel flow in the quasi-symmetric and Mirror configurations of HSX. United States. doi:10.1088/1361-6587/aab4c7.
Kumar, S. T. A., Dobbins, T. J., Talmadge, J. N., Wilcox, R. S., and Anderson, D. T. Wed . "Radial electric field and ion parallel flow in the quasi-symmetric and Mirror configurations of HSX". United States. doi:10.1088/1361-6587/aab4c7. https://www.osti.gov/servlets/purl/1432157.
@article{osti_1432157,
title = {Radial electric field and ion parallel flow in the quasi-symmetric and Mirror configurations of HSX},
author = {Kumar, S. T. A. and Dobbins, T. J. and Talmadge, J. N. and Wilcox, R. S. and Anderson, D. T.},
abstractNote = {In this paper, the radial electric field and the ion mean parallel flow are obtained in the helically symmetric experiment stellarator from toroidal flow measurements of C+6 ion at two locations on a flux surface, using the Pfirsch–Schlüter effect. Results from the standard quasi-helically symmetric magnetic configuration are compared with those from the Mirror configuration where the quasi-symmetry is deliberately degraded using auxiliary coils. For similar injected power, the quasi-symmetric configuration is observed to have significantly lower flows while the experimental observations from the Mirror geometry are in better agreement with neoclassical calculations. Finally, indications are that the radial electric field near the core of the quasi-symmetric configuration may be governed by non-neoclassical processes.},
doi = {10.1088/1361-6587/aab4c7},
journal = {Plasma Physics and Controlled Fusion},
number = 5,
volume = 60,
place = {United States},
year = {2018},
month = {3}
}

Journal Article:
Free Publicly Available Full Text
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Cited by: 1 work
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Figures / Tables:

Figure 1 Figure 1: (a) Poloidal cross-section of HSX magnetic flux surfaces where the flow measurements are made. Vertical shaded band represents approximate 1/e width of the diagnostic hydrogen neutral beam. Red and green dots represent inboard and outboard measurement locations respectively. (b) The Pfirsch-Schlüter factor, h, calculated at the measurement locationsmore » for QHS (closed squares) and Mirror (open squares) geometries. A synthetic diagnostic model is used to obtain weighted average values along the sight-line-beam intersection. Horizontal ‘error bars’ represent the radial averaging.« less

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Works referenced in this record:

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