Balmer-α spectrum measurements of the LHD one-third ion source

Journal Article · Mon Feb 15 04:00:00 EST 2016 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4932319· OSTI ID:22482929

Kenmotsu, T. ^[1]; Kisaki, M.; Nakano, H.; Tsumori, K. ^[2]; Nishiura, M. ^[3]

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1. School of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan)
2. National Institute for Fusion Science, Toki, Gifu 509-5202 (Japan)
3. Graduate School of Frontier Science, The University of Tokyo, Kashiwa, 277-8561 Chiba (Japan)

Wavelength spectra of Balmer-α light from plasmas in the extraction region of the Large Helical Device-R&D negative ion source, or the LHD one-third ion source have exhibited a blue shift as a negative bias voltage was applied to the plasma grid. The blue shift increased as the negative bias voltage with respect to the local plasma potential was increased. The measured spectra were compared with the velocity distributions of surface reflected hydrogen atoms calculated by atomic collisions in amorphous target code. The arc power and the source H{sub 2} pressure also affected the shift and broadening in the observed Balmer-α spectra. The possibility of identifying the negative hydrogen ions produced at the low work function plasma grid surface by high resolution spectroscopy is discussed.

• OSTI ID: 22482929
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 2 Vol. 87; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ATOM COLLISIONS
GRIDS
HYDROGEN
HYDROGEN IONS
ION SOURCES
LHD DEVICE
PLASMA
PLASMA POTENTIAL
SPECTRA
SPECTROSCOPY