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

doi:10.1088/1741-4326/ad6914

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. KurodaY. Nagashima, T. Ido, T. Kariya, A. Ejiri, S. Murakami, A. Fukuyama, Y. Kosuga

Advanced Fusion Research Center

Research output: Contribution to journal › Article › peer-review

4 Citations (Scopus)

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 × 10¹⁸ 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.

Original language	English
Article number	106020
Journal	Nuclear Fusion
Volume	64
Issue number	10
DOIs	https://doi.org/10.1088/1741-4326/ad6914
Publication status	Published - Oct 2024

All Science Journal Classification (ASJC) codes

Nuclear and High Energy Physics
Condensed Matter Physics

Access to Document

10.1088/1741-4326/ad6914

Cite this

Onchi, T., Idei, H., Hanada, K., Watanabe, O., Miyata, R., Zhang, Y., Koide, Y., Otsuka, Y., Yamaguchi, T., Higashijima, A., Nagata, T., Sekiya, I., Shimabukuro, S., Niiya, I., Kono, K., Zennifa, F., Nakamura, K., Ikezoe, R., Hasegawa, M., ... Kosuga, Y. (2024). Electron cyclotron current start-up using a retarding electric field in the QUEST spherical tokamak. Nuclear Fusion, 64(10), Article 106020. https://doi.org/10.1088/1741-4326/ad6914

Onchi, T , Idei, H , Hanada, K, Watanabe, O, Miyata, R, Zhang, Y, Koide, Y, Otsuka, Y, Yamaguchi, T, Higashijima, A, Nagata, T, Sekiya, I, Shimabukuro, S, Niiya, I, Kono, K, Zennifa, F, Nakamura, K, Ikezoe, R , Hasegawa, M, Kuroda, K, Nagashima, Y , Ido, T, Kariya, T, Ejiri, A, Murakami, S, Fukuyama, A & Kosuga, Y 2024, 'Electron cyclotron current start-up using a retarding electric field in the QUEST spherical tokamak', Nuclear Fusion, vol. 64, no. 10, 106020. https://doi.org/10.1088/1741-4326/ad6914

@article{9caaae83ea0f46f7b411758e6e4e3157,

title = "Electron cyclotron current start-up using a retarding electric field in the QUEST spherical tokamak",

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 Te ≈ 1 keV at electron density ne > 1.0 × 1018 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 = "electron cyclotron heating, plasma current start-up, spherical tokamak",

author = "T. Onchi and H. Idei and K. Hanada and O. Watanabe and R. Miyata and Y. Zhang and Y. Koide and Y. Otsuka and T. Yamaguchi and A. Higashijima and T. Nagata and I. Sekiya and S. Shimabukuro and I. Niiya and K. Kono and F. Zennifa and K. Nakamura and R. Ikezoe and M. Hasegawa and K. Kuroda and Y. Nagashima and T. Ido and T. Kariya and A. Ejiri and S. Murakami and A. Fukuyama and Y. Kosuga",

note = "Publisher Copyright: {\textcopyright} 2024 The Author(s). Published by IOP Publishing Ltd on behalf of the IAEA",

year = "2024",

month = oct,

doi = "10.1088/1741-4326/ad6914",

language = "English",

volume = "64",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing Ltd.",

number = "10",

}

TY - JOUR

T1 - Electron cyclotron current start-up using a retarding electric field in the QUEST spherical tokamak

AU - Onchi, T.

AU - Idei, H.

AU - Hanada, K.

AU - Watanabe, O.

AU - Miyata, R.

AU - Zhang, Y.

AU - Koide, Y.

AU - Otsuka, Y.

AU - Yamaguchi, T.

AU - Higashijima, A.

AU - Nagata, T.

AU - Sekiya, I.

AU - Shimabukuro, S.

AU - Niiya, I.

AU - Kono, K.

AU - Zennifa, F.

AU - Nakamura, K.

AU - Ikezoe, R.

AU - Hasegawa, M.

AU - Kuroda, K.

AU - Nagashima, Y.

AU - Ido, T.

AU - Kariya, T.

AU - Ejiri, A.

AU - Murakami, S.

AU - Fukuyama, A.

AU - Kosuga, Y.

PY - 2024/10

Y1 - 2024/10

N2 - 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 Te ≈ 1 keV at electron density ne > 1.0 × 1018 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.

AB - 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 Te ≈ 1 keV at electron density ne > 1.0 × 1018 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.

KW - electron cyclotron heating

KW - plasma current start-up

KW - spherical tokamak

UR - https://www.scopus.com/pages/publications/85202432711

UR - https://www.scopus.com/inward/citedby.url?scp=85202432711&partnerID=8YFLogxK

U2 - 10.1088/1741-4326/ad6914

DO - 10.1088/1741-4326/ad6914

M3 - Article

AN - SCOPUS:85202432711

SN - 0029-5515

VL - 64

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 10

M1 - 106020

ER -

Electron cyclotron current start-up using a retarding electric field in the QUEST spherical tokamak

Abstract

All Science Journal Classification (ASJC) codes

Access to Document

Other files and links

Fingerprint

Cite this