skip to main content

Title: Doppler shift measurement of Balmer-alpha line spectrum emission from a plasma in a negative hydrogen ion source

Balmer-α light emission from the extraction region of the LHD one-third ion source has shown a characteristic Doppler broadening in the wavelength spectrum detected by a high resolution spectrometer. The spectrum resembles Gaussian distribution near the wavelength of the intensity peak, while it has an additional component of a broader foot. The measured broadening near the wavelength of the intensity peak corresponds to 0.6 eV hydrogen atom temperature. The spectrum exhibits a larger expansion in the blue wing which becomes smaller when the line of sight is tilted toward the driver region from the original observation axis parallel to the plasma grid. A surface collision simulation model predicts the possibility of hydrogen reflection at the plasma grid surface to form a broad Balmer-α light emission spectrum.
Authors:
;  [1] ; ; ;  [2] ;  [3]
  1. Graduate School of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 Japan (Japan)
  2. National Institute for Fusion Science, Toki, Gifu (Japan)
  3. Graduate School of Frontier Sciences, The Universtiy of Tokyo, Chiba 277-8561 (Japan)
Publication Date:
OSTI Identifier:
22391394
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1655; Journal Issue: 1; Conference: NIBS 2014: 4. International Symposium on Negative Ions, Beams and Sources, Garching (Germany), 6-10 Oct 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ATOMS; COMPUTERIZED SIMULATION; DOPPLER BROADENING; EMISSION SPECTRA; EV RANGE; GAUSS FUNCTION; HYDROGEN; HYDROGEN IONS; ION SOURCES; LHD DEVICE; PLASMA; REFLECTION; SURFACES; VISIBLE RADIATION