Development of a New Far Infrared Laser Interferometer in Heliotron J and First Results

• OHTANI Yoshiaki

  Graduate School of Energy Science, Kyoto University

• OHSHIMA Shinsuke

  Institute of Advanced Energy, Kyoto University

• ASAVATHAVORNVANIT Nuttasart

  Graduate School of Energy Science, Kyoto University

• AKIYAMA Tsuyoshi

  National Institute for Fusion Science

• MINAMI Takashi

  Institute of Advanced Energy, Kyoto University

• TANAKA Kenji

  National Institute for Fusion Science

• NAGASAKI Kazunobu

  Institute of Advanced Energy, Kyoto University

• SHI Nan

  Institute of Plasma Physics, Chinese Academy of Sciences

• MIZUUCHI Tohru

  Institute of Advanced Energy, Kyoto University

• MARUSHCHENKO Nikolai. B.

  Max-Planck-Institute for Plasma Physics

• KOBAYASHI Shinji

  Institute of Advanced Energy, Kyoto University

• OKADA Hiroyuki

  Institute of Advanced Energy, Kyoto University

• KADO Shinnichiro

  Institute of Advanced Energy, Kyoto University

• YAMAMOTO Satoshi

  Institute of Advanced Energy, Kyoto University

• ZANG Linge

  Institute of Advanced Energy, Kyoto University

• WEIR Gavin M.

  Institute of Advanced Energy, Kyoto University

• KENMOCHI Naoki

  Graduate School of Energy Science, Kyoto University

• KONOSHIMA Shigeru

  Institute of Advanced Energy, Kyoto University

• NAKAMURA Yuji

  Graduate School of Energy Science, Kyoto University

• TURKIN Yuriy

  Max-Planck-Institute for Plasma Physics

• SANO Fumimichi

  Institute of Advanced Energy, Kyoto University

Abstract

A new far infrared (FIR) laser interferometer with high time resolution has been developed in Heliotron J for measuring high performance plasmas. The FIR laser interferometer is a heterodyne-type Michelson interferometer with a 1 MHz intermediate frequency. The interferometer uses a super rotating grating and the viewing chord passes through an off-axis position. Refraction in high density plasma is estimated using the TRAVIS ray-tracing code. The results suggest that it is possible to extend the range of the interferometer up to 1.5×10²⁰ m⁻³. The first line-averaged plasma density measurements using the FIR laser interferometer have been made in ECH and NBI heated plasmas. The relative change in the density profile shape is evaluated from the ratio of the line-averaged density obtained by the FIR laser and microwave interferometer with a different viewing chord. The difference in the measurements suggests that a more peaked density profile is formed in NBI plasma than in ECH + NBI plasma, which is in agreement with Nd:YAG Thomson scattering measurements.

Journal

• Plasma and Fusion Research

  Plasma and Fusion Research 10 (0), 1402091-1402091, 2015

  The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

• FIR interferometer
• plasma diagnostics
• electron density
• helical device
• Heliotron

Details

• CRID: 1390282680229728128
• NII Article ID: 130005292404
• DOI: 10.1585/pfr.10.1402091
• ISSN: 18806821
• Web Site: https://www.jstage.jst.go.jp/article/pfr/10/0/10_1402091/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed