Abstract
Plasma start-up experiments using the lower hybrid wave (LHW) were performed on the TST-2 spherical tokamak. Two capacitively-coupled combline antennas (outboard-launch and top-launch) are presently being used. Bottom-launch can be simulated using the top-launch antenna with reversed toroidal field. The unexpectedly good result of the simulated bottom-launch case was investigated by a combined ray-tracing and Fokker-Planck analysis. In the case of simulated bottom-launch the parallel index of refraction (n||) downshifts initially, but because of the plateau formed by the upshifted n|| LHW after reflecting from the cut-off layer at the bottom of the plasma, strong absorption of the low n|| LHW occurs during the first pass through the plasma, generating a distribution function which extends to very high energies.
Original language | English (US) |
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Title of host publication | 23rd Topical Conference on Radiofrequency Power in Plasmas |
Editors | Paul T. Bonoli, Robert I. Pinsker, Xiaojie Wang |
Publisher | American Institute of Physics Inc. |
ISBN (Electronic) | 9780735420137 |
DOIs | |
State | Published - Sep 16 2020 |
Event | 23rd Topical Conference on Radiofrequency Power in Plasmas - Hefei, China Duration: May 14 2019 → May 17 2019 |
Publication series
Name | AIP Conference Proceedings |
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Volume | 2254 |
ISSN (Print) | 0094-243X |
ISSN (Electronic) | 1551-7616 |
Conference
Conference | 23rd Topical Conference on Radiofrequency Power in Plasmas |
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Country/Territory | China |
City | Hefei |
Period | 5/14/19 → 5/17/19 |
Funding
This work was supported in part by Japan/US Cooperation in Fusion Research and Development, Japan Ssociety for the Promotion of Science Grants-in-Aid for Scientific Research (S) 21226021 and (A) 21246137, US Department of Energy Cooperative Agreement DE-AC03-97ER-54411, National Institute for Fusion Science Collaboration Research Programs NIFS14KOCR001, NIFS18KOAR022 and NIFS16KNWR 002. Collaborations with P. Bonoli, J. Wright, and J. Lee at MIT on GENRAY/CQL3D calculations are gratefully acknowledged.
ASJC Scopus subject areas
- General Physics and Astronomy