O-X-B Heating of Overdense Plasmas by 54.5 GHz Electron Cyclotron Waves in CHS

• YOSHIMURA Yasuo

  National Institute for Fusion Science

• NAGASAKI Kazunobu

  Institute of Advanced Energy, Kyoto University

• AKIYAMA Tsuyoshi

  National Institute for Fusion Science

• ISOBE Mitsutaka

  National Institute for Fusion Science

• SHIMIZU Akihiro

  National Institute for Fusion Science

• SUZUKI Chihiro

  National Institute for Fusion Science

• TAKAHASHI Chihiro

  National Institute for Fusion Science

• NAGAOKA Kenichi

  National Institute for Fusion Science

• NISHIMURA Shin

  National Institute for Fusion Science

• MINAMI Takashi

  National Institute for Fusion Science

• MATSUOKA Keisuke

  National Institute for Fusion Science

• OKAMURA Shoichi

  National Institute for Fusion Science

• CHS group

  National Institute for Fusion Science

• KUBO Shin

  National Institute for Fusion Science

• SHIMOZUMA Takashi

  National Institute for Fusion Science

• IGAMI Hiroe

  National Institute for Fusion Science

• NOTAKE Takashi

  National Institute for Fusion Science

• MUTOH Takashi

  National Institute for Fusion Science

Abstract

An evident increase in the plasma stored energy by applying 54.5 GHz electron cyclotron (EC) waves has been observed in plasmas sustained by neutral beam injection (NBI) with line-averaged electron density of above 3.8 × 10¹⁹ m^-3, that is, the cut-off density of the 54.5 GHz waves, in the Compact Helical System (CHS). The heating effect can be seen even for high-density over 8 × 10¹⁹ m^-3: more than twice the cut-off density. The 54.5 GHz EC-wave beam is obliquely injected to high-density plasmas. The scanning of the EC-wave beam direction gives the evident increase in the stored energy at the beam direction where the leakage EC-wave power from the CHS vacuum vessel becomes almost the minimum. The most possible cause for this heating mechanism is an electron Bernstein wave heating via an Ordinary - eXtraordinary - Bernstein (O-X-B) mode conversion process.

Journal

• Plasma and Fusion Research

  Plasma and Fusion Research 1 029-029, 2006

  The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

• ECH
• overdense plasma
• cut-off density
• CHS
• O-X-B
• electron Bernstein wave

Details

• CRID: 1390001205254455296
• NII Article ID: 130002058811
• DOI: 10.1585/pfr.1.029
• ISSN: 18806821
• HANDLE: 10655/3865
• Web Site: https://nifs-repository.repo.nii.ac.jp/records/485
• Web Site: http://www.jstage.jst.go.jp/article/pfr/1/0/1_0_029/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed