| Item type |
学術雑誌論文 / Journal Article(1) |
| 公開日 |
2023-09-14 |
| タイトル |
|
|
タイトル |
Effects of toroidally-distributed-divertor biasing on scrape-off-layer (SOL) current drive, divertor particle flux and fast electron confinement in the QUEST spherical tokamak |
|
言語 |
en |
| 言語 |
|
|
言語 |
eng |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
divertor biasing |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
scrape off layer (SOL) |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
SOL current |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
divertor particle flux |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
fast electron losses |
| キーワード |
|
|
言語 |
en |
|
主題Scheme |
Other |
|
主題 |
QUEST spherical tokamak |
| 資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
|
資源タイプ |
journal article |
| 著者 |
TOI, Kazuo
ONCHI, Takumi
ZUSHI, Hideki
KURODA, Kengo
IDEI, Hiroshi
HANADA, Kazuaki
HASEGAWA, Makoto
KOJIMA, Shinichiro
IKEZOE, Ryuya
IDO, Takeshi
KAWASAKI, Shoji
HIGASHIJIMA, Aki
QUEST Experiment Group
|
| 著者ID |
|
|
内容記述タイプ |
Other |
|
内容記述 |
ORCID 0000-0002-8244-8305 |
| 抄録 |
|
|
内容記述タイプ |
Abstract |
|
内容記述 |
A novel divertor biasing by four biasing plates distributed toroidally (TDDB) on the upper divertor target plate is applied to low density tokamak plasmas started-up by 28 GHz 2nd harmonic electron cyclotron current drive (ECCD) in a quasi-double null configuration of the QUEST spherical tokamak (ST). In the ST plasmas of line averaged electron density <${n_e}$ > ∼0.7–1 × 1018 m−3, about 20%–40% of the current ${I_{{\text{bias}}}}$ driven by ∼85 V sawtooth bias voltage reaches the lower divertor plate along the biased scrape-off-layer (SOL) flux tube as the SOL current ${I_{{\text{SOL}}}}$. The fact ${I_{{\text{SOL}}}}$ is noticeably lower than ${I_{\text{bias}}}{\text{ }}$ indicates an appreciable leakage of parallel current from the biased SOL flux tube. The leakage currents in the toroidal and radial directions are confirmed by detection of them using the unbiased plates in the TDDB experiments. From the ion saturation current density profile obtained by a divertor Langmuir probe array, the fall-off lengths of divertor particle flux are estimated together with the strike line position. Total particle flux to the upper divertor, evaluated by the integrated ion saturation current density profile is reduced by up to 45% during positive biasing of the TDDB, depending on the position of the strike line to the biased plate. In addition, the TDDB also induces a noticeable loss of fast electrons produced by ECCD, leading to an ∼2% reduction in the maximum toroidal current of the ST plasma compared to a shot without the TDDB. Reduction of the divertor particle flux and enhancement of the fast electron losses are thought to be dominantly caused by E$ \times B$ drift induced by the TDDB. In the present experimental conditions, the effects of magnetic perturbations produced by the SOL currents on the fast electron losses can be neglected because of a too small SOL current. |
|
言語 |
en |
| 書誌情報 |
en : Nuclear Fusion
巻 63,
号 10,
p. 106018,
発行日 2023-09-07
|
| 出版者 |
|
|
出版者 |
IOP Publishing |
|
言語 |
en |
| ISSN |
|
|
収録物識別子タイプ |
ISSN |
|
収録物識別子 |
1741-4326 |
| 書誌レコードID |
|
|
収録物識別子タイプ |
NCID |
|
収録物識別子 |
AA00759871 |
| DOI |
|
|
関連タイプ |
isIdenticalTo |
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
https://doi.org/10.1088/1741-4326/acee13 |
| 権利 |
|
|
言語 |
en |
|
権利情報 |
© 2023 The Author(s). Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attributionto the author(s) and the title of the work, journal citation and DOI. |
| 情報源 |
|
|
|
言語 |
en |
|
|
関連名称 |
Kazuo Toi et al 2023 Nucl. Fusion 63 106018 |
| 関連サイト |
|
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
https://doi.org/10.1088/1741-4326/acee13 |
|
|
関連名称 |
Publisher version |
| 著者版フラグ |
|
|
出版タイプ |
VoR |
|
出版タイプResource |
http://purl.org/coar/version/c_970fb48d4fbd8a85 |
| NAIS |
|
|
|
en |
|
|
13890 |
13890_Nucl.Fusion.pdf (5 MB)
.png)
