Nuclear Fusion (Jan 2024)
Electron cyclotron current start-up using a retarding electric field in the QUEST spherical tokamak
- T. Onchi,
- H. Idei,
- K. Hanada,
- O. Watanabe,
- R. Miyata,
- Y. Zhang,
- Y. Koide,
- Y. Otsuka,
- T. Yamaguchi,
- A. Higashijima,
- T. Nagata,
- I. Sekiya,
- S. Shimabukuro,
- I. Niiya,
- K. Kono,
- F. Zennifa,
- K. Nakamura,
- R. Ikezoe,
- M. Hasegawa,
- K. Kuroda,
- Y. Nagashima,
- T. Ido,
- T. Kariya,
- A. Ejiri,
- S. Murakami,
- A. Fukuyama,
- Y. Kosuga
Affiliations
- T. Onchi
- ORCiD
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- H. Idei
- ORCiD
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- K. Hanada
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- O. Watanabe
- Graduate School of Frontier Sciences, The University of Tokyo , Kashiwa, Japan
- R. Miyata
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University , Kasuga, Japan
- Y. Zhang
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University , Kasuga, Japan
- Y. Koide
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University , Kasuga, Japan
- Y. Otsuka
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University , Kasuga, Japan
- T. Yamaguchi
- Interdisciplinary Graduate School of Engineering Sciences, Kyushu University , Kasuga, Japan
- A. Higashijima
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- T. Nagata
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- I. Sekiya
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- S. Shimabukuro
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- I. Niiya
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- K. Kono
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- F. Zennifa
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- K. Nakamura
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- R. Ikezoe
- ORCiD
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- M. Hasegawa
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- K. Kuroda
- ORCiD
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan; Japan Coast Guard Academy , Kure, Japan
- Y. Nagashima
- ORCiD
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- T. Ido
- ORCiD
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- T. Kariya
- Plasma Research Center, University of Tsukuba , Tsukuba, Japan
- A. Ejiri
- Graduate School of Frontier Sciences, The University of Tokyo , Kashiwa, Japan
- S. Murakami
- ORCiD
- Department of Nuclear Engineering, Kyoto University , Kyoto, Japan
- A. Fukuyama
- ORCiD
- Department of Nuclear Engineering, Kyoto University , Kyoto, Japan
- Y. Kosuga
- ORCiD
- Research Institute for Applied Mechanics, Kyushu University , Kasuga, Japan
- DOI
- https://doi.org/10.1088/1741-4326/ad6914
- Journal volume & issue
-
Vol. 64,
no. 10
p. 106020
Abstract
The plasma current start-up experiment is conducted through electron cyclotron (EC) heating in the QUEST spherical tokamak. During the EC heating, the application of a toroidal electric field in the opposite direction to the plasma current effectively inhibits the growth of energetic electrons. Observations show rapid increases in plasma current and hard x-ray count immediately following the cancellation of the retarding electric field. When a compact tokamak configuration maintains equilibrium on the high field side, along with the retarding field, it leads to effective bulk electron heating. This heating achieved an electron temperature of T _e ≈ 1 keV at electron density n _e > 1.0 × 10 ^18 m ^−3 . Ray tracing of the EC wave verifies that more power absorption into plasma through a single-pass occurs around the second resonance layer with higher values of electron density and temperature.
Keywords
