HFS injection of X-mode for EBW conversion in QUEST

Hatem Elserafy; Kazuaki Hanada; Kengoh Kuroda; Hiroshi Idei; Ryota Yoneda; Canbin Huang; Shinichiro Kojima; Makoto Hasegawa; Yoshihiko Nagashima; Takumi Onchi; Ryuya Ikezoe; Aki Higashijima; Takahiro Nagata; Shoji Kawasaki; Shun Shimabukuro; Nicola Bertelli; Masayuki Ono

doi:10.1585/pfr.14.1205038

HFS injection of X-mode for EBW conversion in QUEST

Hatem Elserafy
, Kazuaki Hanada
, Kengoh Kuroda
, Hiroshi Idei
, Ryota Yoneda
, Canbin Huang
, Shinichiro Kojima
, Makoto Hasegawa
, Yoshihiko Nagashima
, Takumi Onchi
, Ryuya Ikezoe
, Aki Higashijima
, Takahiro Nagata
, Shoji Kawasaki
, Shun Shimabukuro
, Nicola Bertelli
, Masayuki Ono

PPPL NSTX

Princeton University

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

Abstract

High field side (HFS) injection of eXtra-ordinary X-mode for electron Bernstein wave (EBW) conversion was conducted in the QUEST tokamak. Radio frequency (RF; 8.2 GHz) power was delivered from the low field side (LFS) to the high field side HFS through waveguides, and from the HFS placed 20 cm above the midplane of the vacuum vessel. The aim was to compare the RF launches from the LFS and HFS. The plasma brightness, measured by a fast camera, as well as the H _α signal captured along the mid-plane, was noticeably higher in the HFS launch than in the LFS launch. The HFS injection achieved a plasma current of approximately 130 A, versus 35A in the LFS injection. The electron density n _e predicted from the position of the upper hybrid resonance agreed with the line-averaged n _e measured by an interferometer, confirming the effective conversion and subsequent damping of the EBW mode. The RF leakage of the HFS injection was less than one-sixth that of the LFS injection. These results indicate that HFS delivers better RF coupling and conversion efficiency to EBW than LFS injection. Such efficient plasma heating via EBW will significantly enhance the plasma production.

Original language	American English
Article number	1205038
Journal	Plasma and Fusion Research
Volume	14
Issue number	1
DOIs	https://doi.org/10.1585/pfr.14.1205038
State	Published - 2019

ASJC Scopus subject areas

Condensed Matter Physics

Keywords

EBW
HFS launch
Plasma production

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10.1585/pfr.14.1205038

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Elserafy, H., Hanada, K., Kuroda, K., Idei, H., Yoneda, R., Huang, C., Kojima, S., Hasegawa, M., Nagashima, Y., Onchi, T., Ikezoe, R., Higashijima, A., Nagata, T., Kawasaki, S., Shimabukuro, S., Bertelli, N., & Ono, M. (2019). HFS injection of X-mode for EBW conversion in QUEST. Plasma and Fusion Research, 14(1), Article 1205038. https://doi.org/10.1585/pfr.14.1205038

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title = "HFS injection of X-mode for EBW conversion in QUEST",

abstract = " High field side (HFS) injection of eXtra-ordinary X-mode for electron Bernstein wave (EBW) conversion was conducted in the QUEST tokamak. Radio frequency (RF; 8.2 GHz) power was delivered from the low field side (LFS) to the high field side HFS through waveguides, and from the HFS placed 20 cm above the midplane of the vacuum vessel. The aim was to compare the RF launches from the LFS and HFS. The plasma brightness, measured by a fast camera, as well as the H α signal captured along the mid-plane, was noticeably higher in the HFS launch than in the LFS launch. The HFS injection achieved a plasma current of approximately 130 A, versus 35A in the LFS injection. The electron density n e predicted from the position of the upper hybrid resonance agreed with the line-averaged n e measured by an interferometer, confirming the effective conversion and subsequent damping of the EBW mode. The RF leakage of the HFS injection was less than one-sixth that of the LFS injection. These results indicate that HFS delivers better RF coupling and conversion efficiency to EBW than LFS injection. Such efficient plasma heating via EBW will significantly enhance the plasma production.",

keywords = "EBW, HFS launch, Plasma production",

author = "Hatem Elserafy and Kazuaki Hanada and Kengoh Kuroda and Hiroshi Idei and Ryota Yoneda and Canbin Huang and Shinichiro Kojima and Makoto Hasegawa and Yoshihiko Nagashima and Takumi Onchi and Ryuya Ikezoe and Aki Higashijima and Takahiro Nagata and Shoji Kawasaki and Shun Shimabukuro and Nicola Bertelli and Masayuki Ono",

note = "Publisher Copyright: {\textcopyright} 2019 The Japan Society of Plasma Science and Nuclear Fusion Research.",

year = "2019",

doi = "10.1585/pfr.14.1205038",

language = "American English",

volume = "14",

journal = "Plasma and Fusion Research",

issn = "1880-6821",

publisher = "The Japan Society of Plasma Science and Nuclear Fusion Research (JSPF)",

number = "1",

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TY - JOUR

T1 - HFS injection of X-mode for EBW conversion in QUEST

AU - Elserafy, Hatem

AU - Hanada, Kazuaki

AU - Kuroda, Kengoh

AU - Idei, Hiroshi

AU - Yoneda, Ryota

AU - Huang, Canbin

AU - Kojima, Shinichiro

AU - Hasegawa, Makoto

AU - Nagashima, Yoshihiko

AU - Onchi, Takumi

AU - Ikezoe, Ryuya

AU - Higashijima, Aki

AU - Nagata, Takahiro

AU - Kawasaki, Shoji

AU - Shimabukuro, Shun

AU - Bertelli, Nicola

AU - Ono, Masayuki

PY - 2019

Y1 - 2019

N2 - High field side (HFS) injection of eXtra-ordinary X-mode for electron Bernstein wave (EBW) conversion was conducted in the QUEST tokamak. Radio frequency (RF; 8.2 GHz) power was delivered from the low field side (LFS) to the high field side HFS through waveguides, and from the HFS placed 20 cm above the midplane of the vacuum vessel. The aim was to compare the RF launches from the LFS and HFS. The plasma brightness, measured by a fast camera, as well as the H α signal captured along the mid-plane, was noticeably higher in the HFS launch than in the LFS launch. The HFS injection achieved a plasma current of approximately 130 A, versus 35A in the LFS injection. The electron density n e predicted from the position of the upper hybrid resonance agreed with the line-averaged n e measured by an interferometer, confirming the effective conversion and subsequent damping of the EBW mode. The RF leakage of the HFS injection was less than one-sixth that of the LFS injection. These results indicate that HFS delivers better RF coupling and conversion efficiency to EBW than LFS injection. Such efficient plasma heating via EBW will significantly enhance the plasma production.

AB - High field side (HFS) injection of eXtra-ordinary X-mode for electron Bernstein wave (EBW) conversion was conducted in the QUEST tokamak. Radio frequency (RF; 8.2 GHz) power was delivered from the low field side (LFS) to the high field side HFS through waveguides, and from the HFS placed 20 cm above the midplane of the vacuum vessel. The aim was to compare the RF launches from the LFS and HFS. The plasma brightness, measured by a fast camera, as well as the H α signal captured along the mid-plane, was noticeably higher in the HFS launch than in the LFS launch. The HFS injection achieved a plasma current of approximately 130 A, versus 35A in the LFS injection. The electron density n e predicted from the position of the upper hybrid resonance agreed with the line-averaged n e measured by an interferometer, confirming the effective conversion and subsequent damping of the EBW mode. The RF leakage of the HFS injection was less than one-sixth that of the LFS injection. These results indicate that HFS delivers better RF coupling and conversion efficiency to EBW than LFS injection. Such efficient plasma heating via EBW will significantly enhance the plasma production.

KW - EBW

KW - HFS launch

KW - Plasma production

UR - https://www.scopus.com/pages/publications/85063647037

UR - https://www.scopus.com/pages/publications/85063647037#tab=citedBy

U2 - 10.1585/pfr.14.1205038

DO - 10.1585/pfr.14.1205038

M3 - Article

SN - 1880-6821

VL - 14

JO - Plasma and Fusion Research

JF - Plasma and Fusion Research

IS - 1

M1 - 1205038

ER -

HFS injection of X-mode for EBW conversion in QUEST

Abstract

ASJC Scopus subject areas

Keywords

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