First Observation of RF-Induced Visible Light Fluctuations

Yuki TORII; Akira EJIRI; Tetsuya MASUDA; Takuya OOSAKO; Makoto SASAKI; Hiroshi TOJO; Hideo NUGA; Yoshiyuki SHIMADA; Nobuyuki SUMITOMO; Jiro TSUJIMURA; Soichiro KAINAGA; Junichi SUGIYAMA; Yuichi TAKASE

doi:10.1585/pfr.2.023

Rapid Communications

First Observation of RF-Induced Visible Light Fluctuations

Yuki TORII, Akira EJIRI, Tetsuya MASUDA, Takuya OOSAKO, Makoto SASAKI, Hiroshi TOJO, Hideo NUGA, Yoshiyuki SHIMADA, Nobuyuki SUMITOMO, Jiro TSUJIMURA, Soichiro KAINAGA, Junichi SUGIYAMA, Yuichi TAKASE

Author information

Yuki TORII
High Temperature Plasma Center, The University of Tokyo
Akira EJIRI
Graduate School of Frontier Sciences, The University of Tokyo
Tetsuya MASUDA
Graduate School of Frontier Sciences, The University of Tokyo
Takuya OOSAKO
Graduate School of Frontier Sciences, The University of Tokyo
Makoto SASAKI
Graduate School of Science, The University of Tokyo
Hiroshi TOJO
Graduate School of Frontier Sciences, The University of Tokyo
Hideo NUGA
Graduate School of Science, The University of Tokyo
Yoshiyuki SHIMADA
Graduate School of Frontier Sciences, The University of Tokyo
Nobuyuki SUMITOMO
Graduate School of Science, The University of Tokyo
Jiro TSUJIMURA
Graduate School of Frontier Sciences, The University of Tokyo
Soichiro KAINAGA
Graduate School of Science, The University of Tokyo
Junichi SUGIYAMA
Graduate School of Frontier Sciences, The University of Tokyo
Yuichi TAKASE
Graduate School of Frontier Sciences, The University of Tokyo

Keywords: high harmonic fast wave, photodiode, density fluctuation, visible light modulation, spherical tokamak, TST-2

JOURNAL FREE ACCESS

2007 Volume 2 Pages 023

DOI https://doi.org/10.1585/pfr.2.023

Details

Abstract

In order to detect rf modulation of visible light emitted from plasma, a high-speed photodiode measurement system was developed. The system is located outside the vacuum vessel of the TST-2 spherical tokamak and measures visible light emissions through a quartz window. A dedicated amplifier for the photodiode was made. Care was taken to reduce the rf pickup noise. The frequency spectrum of the light signal detected during high harmonic fast wave (HHFW) heating showed modulation by HHFW. This is the first measurement of visible light modulation induced by HHFW, and shows promise for measurement of the rf electric field in the plasma core.

Corresponding author

Register with J-STAGE for free!