Abstract
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. Indications are that the radial electric field near the core of the quasi-symmetric configuration may be governed by non-neoclassical processes.
Original language | English |
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Article number | 054012 |
Journal | Plasma Physics and Controlled Fusion |
Volume | 60 |
Issue number | 5 |
DOIs | |
State | Published - Mar 23 2018 |
Funding
The authors would like to thank F S B Anderson and K Likin for help with machine operation. The material presented in this paper is based upon work supported by the US Department of Energy, Office of Science, Office of Fusion Energy Science under award number DE-FG02-93ER54222. Data for figures included in this publication are available for access at http://hsx.wisc.edu/HSXPublicationData.
Keywords
- flows
- radial electric field
- stellerator