Plasma and Fusion Research

Volume 13, 1202103 (2018)

Rapid Communications


Observation of the Spatial Profile of Deuterium/Hydrogen Ratio Using Bulk Charge Exchange Emission
Kotaro YAMASAKI, Katsumi IDA1), Mikirou YOSHINUMA1) and Tatsuya KOBAYASHI1)
Research Institute for Applied Mechanics, Kyushu University, Kasuga Kohen, Kasuga, Fukuoka 816-8580, Japan
1)
National Institute for Fusion Science, Toki 509-5292, Japan
(Received 3 July 2018 / Accepted 22 July 2018 / Published 10 August 2018)

Abstract

Spatial profile of deuterium/hydrogen (D/H) ratio is observed using the charge exchange emission of bulk deuterium/hydrogen ion and neutral beam perpendicularly injected into the torus plasma. Neutral beam injection (NBI) is turned on and off in order to subtract the deuterium/hydrogen emission from the plasma edge. The number of fitting parameters for the subtracted spectral signal is reduced from 12 to 3 by assuming that the bulk ion temperature and velocity are the same as those of the carbon ions (C6+). The initial result observed in Large Helical Device (LHD) plasma indicates that D/H ratio is constant in radial direction and is the same as that observed from passive spectroscopic measurement when the tangential NBI or the pellet injection are absent.


Keywords

hydrogen isotope ratio, Large Helical Device

DOI: 10.1585/pfr.13.1202103


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