EPJ Web of Conferences (Jan 2015)

Direct measurement of refracted trajectory of transmitting electron cyclotron beam through plasma on the Large Helical Device

  • Takahashi Hiromi,
  • Kubo Shin,
  • Shimozuma Takashi,
  • Igami Hiroe,
  • Yoshimura Yasuo,
  • Ito Satoshi,
  • Kobayasi Sakuji,
  • Mizuno Yoshinori,
  • Okada Kohta,
  • Kamio Shuji,
  • Mutoh Takashi,
  • Osakabe Masaki,
  • Nagasaki Kazunobu,
  • Marushchenko Nikolai B.,
  • Turkin Yuriy

DOI
https://doi.org/10.1051/epjconf/20158702019
Journal volume & issue
Vol. 87
p. 02019

Abstract

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The electron-cyclotron (EC) -beam refraction due to the presence of plasma was investigated in the Large Helical Device. The transmitted-EC-beam measurement system was constructed and the beam pattern on the opposite side of the irradiated surface was measured using an IR camera. Clear dependence of the EC-beam refraction on the electron density was observed and the beam shift in the toroidal direction showed good agreement with the ray-trace calculation of TRAVIS. The influence of the peripheral density profile and the thermal effect on the beam refraction were discussed.