TY - JOUR
T1 - Full noninductive plasma start-up using electron Bernstein wave current drive on high-field side injection in QUEST
AU - Junyao, Zhou
AU - Kazuaki, Hanada
AU - Takumi, Onchi
AU - Shinichiro, Kojima
AU - Qilin, Yue
AU - Kengoh, Kuroda
AU - Kaori, Kono
AU - Takeshi, Ido
AU - Ryuya, Ikezoe
AU - Makoto, Hasegawa
AU - Hiroshib, Idei
AU - Yoshihiko, Nagashima
AU - Izumi, Sekiya
AU - Toshiki, Kinoshita
AU - Aki, Higashijima
AU - Takahiro, Nagata
AU - Sakai, Seiya
N1 - Publisher Copyright:
© 2026 The Author(s). Published by IOP Publishing Ltd on behalf of the IAEA. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
PY - 2026/8
Y1 - 2026/8
N2 - Electron cyclotron wave (ECW) injection is considered an effective auxiliary method for plasma start-up. In QUEST, high-field side (HFS) injection of ECW was conducted to achieve effective mode conversion to electron Bernstein wave (EBW), which can propagate in high-density plasma and provide greater heating/current-drive efficiency than ECW at low electron temperatures. The EBW-driven current, (Formula presented) (Formula presented) whose direction is inverted by toroidal and radial magnetic fields, was clearly observed experimentally, and this characteristic of EBW current drive (EBWCD) played an important role in closed-flux surface formation. The findings are supported by an improved current-density profile model used to reconstruct the current distribution in the open flux surface (OFS) phase. The EBWCD efficiency in the OFS is approximately evaluated 0.014 A W−1 in the OFS phase using a model calculation that includes co- and counter-directed (Formula presented) (Formula presented).
AB - Electron cyclotron wave (ECW) injection is considered an effective auxiliary method for plasma start-up. In QUEST, high-field side (HFS) injection of ECW was conducted to achieve effective mode conversion to electron Bernstein wave (EBW), which can propagate in high-density plasma and provide greater heating/current-drive efficiency than ECW at low electron temperatures. The EBW-driven current, (Formula presented) (Formula presented) whose direction is inverted by toroidal and radial magnetic fields, was clearly observed experimentally, and this characteristic of EBW current drive (EBWCD) played an important role in closed-flux surface formation. The findings are supported by an improved current-density profile model used to reconstruct the current distribution in the open flux surface (OFS) phase. The EBWCD efficiency in the OFS is approximately evaluated 0.014 A W−1 in the OFS phase using a model calculation that includes co- and counter-directed (Formula presented) (Formula presented).
KW - QUEST
KW - electron Bernstein wave (EBW)
KW - electron Bernstein wave current drive (EBWCD)
KW - high-field side (HFS)
KW - noninductive plasma start-up
KW - spherical tokamak (ST)
UR - https://www.scopus.com/pages/publications/105044562252
UR - https://www.scopus.com/pages/publications/105044562252#tab=citedBy
U2 - 10.1088/1741-4326/ae7b57
DO - 10.1088/1741-4326/ae7b57
M3 - Article
AN - SCOPUS:105044562252
SN - 0029-5515
VL - 66
JO - Nuclear Fusion
JF - Nuclear Fusion
IS - 8
M1 - 086019
ER -