Interpretation of spectral emission around 20 nm region from tungsten ions observed in fusion device plasmas
|Title:||Interpretation of spectral emission around 20 nm region from tungsten ions observed in fusion device plasmas||Authors:||Suzuki, C.
Harte, Colm S.
|Permanent link:||http://hdl.handle.net/10197/3692||Date:||24-Aug-2011||Online since:||2012-06-21T15:03:29Z||Abstract:||We have measured extreme ultraviolet (EUV) spectra from tungsten ions around 20 nm region in plasmas produced in the Large Helical Device at the National Institute for Fusion Science. The spectra after injecting a tungsten pellet into a hydrogen plasma were monitored by a grazing incidence spectrometer. Quasicontinuum spectral feature arising from unresolved transition array (UTA) was observed around 20 nm region in plasmas with temperatures below 1.0 keV. This structure is reasonably considered to be the same one as those observed in another tokamak device or laser produced plasmas under low temperature conditions. Atomic structure calculations have been performed for tungsten ions with open 5p, 5s and 4f subshells (W7+–W27+) to interpret this commonly observed feature around 20 nm. Wavelengths and gA values for these transitions were calculated, and their mean wavelengths and extent were compared with the observations, which suggests that the emission largely arises from n = 5–5 transitions in stages lower than W27+.||Funding Details:||Science Foundation Ireland||Type of material:||Journal Article||Publisher:||Institute of Physics||Journal:||Journal of Physics B: Atomic, Molecular and Optical Physics||Volume:||44||Issue:||17||Copyright (published version):||2011 IOP Publishing||Keywords:||EUV spectra; Tungsten||Subject LCSH:||Ultraviolet spectra
|DOI:||10.1088/0953-4075/44/17/175004||Language:||en||Status of Item:||Peer reviewed|
|Appears in Collections:||Physics Research Collection|
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