Spectra of W19+-W32+ observed in the EUV region between 15 and 55 angstrom with an electron-beam ion trap

摘要

We present extreme ultraviolet spectra of highly charged tungsten ions (W19+-W32+) in the wavelength range of 15-55 angstrom obtained with a compact electron-beam ion trap (CoBIT) and a grazing-incidence spectrometer at the National Institute for Fusion Science. The electron energy dependence of the spectra was investigated for electron energies from 490 to 1320 eV. Identification of the observed lines was aided by collisional-radiative (CR) modeling of CoBIT plasma. Good quantitative agreement was obtained between the CR-modeling results and the experimental observations. The ion charge dependence of the 6g-4f, 5g-4f, 5f-4d, 5p-4d, and 4f-4d transition wavelengths were measured.