Survey of EUV Impurity Line Spectra and EUV Bremsstrahlung Continuum in LHD

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Author(s)

    • DONG Chunfeng
    • Department of Fusion Science, Graduate University for Advanced Studies, Toki 509-5292, Gifu, Japan
    • MORITA Shigeru
    • National Institute for Fusion Science, Toki 509-5292, Gifu, Japan
    • GOTO Motoshi
    • National Institute for Fusion Science, Toki 509-5292, Gifu, Japan

Abstract

Radial profiles of impurity spectral line emissions in extreme ultraviolet (EUV) range (60-400 Å) are surveyed for impurity seeded discharges in Large Helical Device (LHD). The line emissions from light impurities such as helium, carbon and neon are located in the edge ergodic layer (1.0 ≤ ρ ≤ 1.2) except for CV and CVI, which are located in region of 0.8 ≤ ρ ≤ 1. In contract, the line emissions from heavy impurities such as iron are widely located over the whole plasma region as a function of ionization energy. On the other hand, the radial profile of bremsstrahlung continuum radiation is also clearly recorded in the EUV spectrum observed from high-density discharges with hydrogen pellet injection. Wavelength intervals available for the absolute sensitivity calibration of the present space-resolved EUV spectrometer system are listed with dominant line emissions which are useful as a wavelength marker.

Journal

  • Plasma and Fusion Research

    Plasma and Fusion Research (6), 2402078-2402078, 2011

    The Japan Society of Plasma Science and Nuclear Fusion Research

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