Plasma and Fusion Research

Volume 14, 1202159 (2019)

Rapid Communications

Effect of Resonant Magnetic Perturbation Field on Energetic Ion Behavior in the Large Helical Device
Kunihiro OGAWA1,2), Sergey A. BOZHENKOV3), Simppa ÄKÄSLOMPOLO3), Mitsutaka ISOBE1,2), Hideo NUGA1), Ryosuke SEKI1,2), Shuji KAMIO1), Yutaka FUJIWARA1), Takeo NISHITANI1), Masaki OSAKABE1,2) and the LHD Experiment Group1)
National Institute for Fusion Science, National Institutes of Natural Sciences, Toki 509-5292, Japan
SOKENDAI (The Graduate University for Advanced Studies), Toki 509-5292, Japan
Max-Planck-Institute for Plasma Physics, Greifswald, Germany
(Received 24 June 2019 / Accepted 2 September 2019 / Published 9 October 2019)


A study of the resonant magnetic perturbation (RMP) effect on transit beam ion behavior is performed using the total neutron emission rate (Sn) measurement of the deuterium plasma in the Large Helical Device. We conducted no RMP field, one-half RMP field, and full RMP field discharges and compared Sn that reflects the global beam ion confinement information. It is determined that owing to the RMP field, Sn decreased by approximately 15 - 30%. Numerical calculations based on the classical confinement of beam ions were performed to investigate the bulk plasma parameter effect on Sn. The calculated Sn shows that the degradation of Sn by RMP is mainly caused by the degradation of the electron temperature owing to island formation which results in a shorter slowing down time of beam ions.


energetic ion confinement, resonant magnetic perturbation field, Large Helical Device, neutron diagnostics

DOI: 10.1585/pfr.14.1202159


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