Contamination of argon x-ray spectra by tungsten and other elements commonly found in tokamaks

Emission lines which appear in the spectral ranges of ground state transitions from n = 2 levels in He- and H-like argon ions are discussed. X-ray transitions from elements commonly found in tokamaks (tungsten, molybdenum, iron and sulphur) which radiate in the wavelength range from 3700-4000 m angstrom are identified by comparison with atomic structure calculations. Individual lines from tungsten charge states in the vicinity of Zn-like W44+ are documented, along with B-like Mo37+. The behaviour of line ratios as a function of electron temperature is examined, in support of the identifications.

Automated summary

This paper discusses emission lines from ground state transitions of He- and H-like argon ions with n=2 levels, as well as X-ray transitions from common elements in tokamaks. By comparing with atomic structure calculations, X-ray transitions from tungsten, molybdenum, iron, and sulfur in the wavelength range of 3700-4000 m angstrom are identified. Individual lines from tungsten charge states near Zn-like W44+ and B-like Mo37+ are documented, and the behavior of line ratios with electron temperature is examined to support the identifications.