1. Modification of the magneto-hydrodynamic equilibrium by the lower-hybrid wave driven fast electrons on the TST-2 spherical tokamak
- Author
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Kotaro Iwasaki, Yi Peng, Osamu Watanabe, Akira Ejiri, Yongtae Ko, Hibiki Yamazaki, Charles P. Moeller, Yuichi Takase, Yuki Aoi, Kyohei Matsuzaki, James H.P. Rice, Yuki Osawa, Yasuo Yoshimura, and Naoto Tsujii
- Subjects
Physics ,Nuclear and High Energy Physics ,Toroid ,Tokamak ,Thomson scattering ,Electron ,Plasma ,Spherical tokamak ,Condensed Matter Physics ,Lower hybrid oscillation ,Computational physics ,law.invention ,Physics::Plasma Physics ,law ,Physics::Space Physics ,Magnetohydrodynamics - Abstract
Presence of a large population of fast particles may qualitatively modify the tokamak equilibrium from the one that can be described by the standard magneto-hydrodynamics (MHD). The kinetic modification of the MHD equilibrium was studied for a lower-hybrid wave driven plasma on the TST-2 spherical tokamak. The analysis was performed using an equilibrium reconstruction method based on an extended MHD model that considers a two-component plasma of bulk MHD fluid and kinetic fast electrons. Scrape-off-layer current appeared naturally in the extended MHD analysis because of the finite electron orbit excursion from the flux surfaces. This reduced the bulk pressure contribution to the toroidal current substantially. The resulting poloidal flux profile was more consistent with that inferred from the Thomson scattering measurement.
- Published
- 2021
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