Plasma and Fusion Research

Volume 14, 1201165 (2019)

Rapid Communications

Variation of Doppler Broadening in High-Temperature Bubbles Created in an ECR Plasma
Atsushi OKAMOTO, Shinji YOSHIMURA1), Kenichiro TERASAKA2) and Masayoshi Y. TANAKA2)
Nagoya University, Nagoya 464-8603, Japan
National Institute for Fusion Science, Toki 509-5292, Japan
Kyushu University, Kasuga 816-8580, Japan
(Received 5 September 2019 / Accepted 28 October 2019 / Published 12 December 2019)


A high dispersion and high time-resolution spectrometer equipped with two slits in output ports is developed to observe variation of Doppler broadening in the high-temperature bubbles [K. Terasaka, et. al., Phys. Plasmas 25, 052113 (2018)]. Reduction of Doppler broadening in a line spectrum of helium ion is experimentally observed when the bubbles emerge in the viewing chord of spectrometer. The results suggest possibilities of ion temperature reduction during the high-temperature bubbles.


ion temperature, high-temperature bubble, electron cyclotron resonance plasma, Doppler spectroscopy, conditional average

DOI: 10.1585/pfr.14.1201165


  • [1] K. Terasaka et al., Phys. Plasmas 25, 052113 (2018).
  • [2] S. Yoshimura et al., Plasma Fusion Res. 10, 3401028 (2015).
  • [3] M.Y. Tanaka et al., Rev. Sci. Instrum 69, 980 (1998).
  • [4] S. Yoshimura et al., J. Plasma Phys. 81, 345810204 (2015).