Observations of x-ray spectra from highly charged tungsten ions in tokamak plasmas
X-ray spectra in the range from 7 angstroms to 10 angstroms from highly charged tungsten (Z=74) ions were observed in the tokamak ASDEX Upgrade. Lines emitted from W(37+) to W(47+) were identified by comparison with ab initio calculations and with the expected ionization equilibrium charge state distribution. Most of the features in the observed spectra coincide with predicted lines. A spectral line of AsI-like W(41+) could be identified as the predominant one for plasmas with between 2.5 keV and 3 keV central electron temperature. The calculations predict clearly separated spectral lines for KrI-like W at about 18.4 angstroms and strong lines between 5.6 angstroms and 6.0 angstroms for all charge states under consideration that can be used for monitoring W densities in the soft x-ray region. Tungsten concentrations in the range of IE-4 were extracted from the emissivities of spectral lines from W(40+) and W(41+).
Bibliographic Reference: Report: IPP 10/7 EN (1997) 16pp.
Availability: Available from the Max-Planck-Institut für Plasmaphysik, 85748 Garching bei München (DE)
Record Number: 199711278 / Last updated on: 1997-10-10
Original language: en
Available languages: en