Observations of x-ray spectra from highly charged tungsten ions in tokamak plasmas
X-ray spectra in the range 7-10 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 As I-like W (41+) could be identified as the predominant one for plasmas with 2.5-3 keV central electron temperature. The calculations predict clearly separated spectral lines for Kr I-like W at about 18.4 angstroms and strong lines between 5.6 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 1E-4 were extracted from the emissivities of spectral lines from W (40+) and W (41+).
Bibliographic Reference: Article: Journal of Physics B, Vol. 30 (1997), pp. 5057-5067
Record Number: 199711725 / Last updated on: 1998-01-20
Original language: en
Available languages: en