Emission Lines in 290–360 nm of Highly Charged Tungsten Ions W20+–W29+

Abstract

Forbidden transitions in the near-UV and visible wavelength of highly charged tungsten (W) ions are potentially useful as novel tungsten diagnostics means of fusion plasmas. Emission lines in 290–360 nm from Wq+ ions interacting with an electron beam of 540–1370 eV are measured, using a compact electron-beam-ion-trap. The charge states of 64 lines are identified as W20+–W29+. A magnetic-dipole (M1) line of W29+ between the excited states (4d84f)[(4d5/2−2)44f7/2]13/2→[(4d5/2−2)44f5/2]13/2 is newly identified; the wavelength is determined as 351.03(10) nm in air. The theoretical wavelength calculated using the multiconfiguration Dirac–Hartree–Fock method is in a good agreement with the measurement.

Experimental and theoretical Ritz–Rydberg analysis of the electronic structure of highly charged ions of lead and bismuth by optical spectroscopy

“…Our study complements recent works from other groups that have investigated various interesting ionic species, for instance [22][23][24][25][26][27][28][29][30], using electron beam ion traps (EBITs). These works also emphasized heavy ions, orbital crossings, and hyperfine structure studies (e.g.…”

“…Lifetime measurements of optical transitions in Mo XXII were reported in [33]. Some more of those investigations are listed here: [34] reported W VI to W VIII spectra; [30] analyzed the spectra of Pm-like W XIV; [23] worked on W VIII; [26] re-assessed earlier work on W XII; [35] analyzed W XIII; W XIV was studied in [36]; in [27] observed spectra from ions W XXI up to W XXX were reported. Spectral data from Yb and W were recorded in [25], where the In-like Yb XXII and W XXVI and Sn-like W XXV were compared with detailed calculations.…”

Partial identification of visible lines from W24+ ions in an electron-beam ion trap

“…However, further studies, especially in multivalent CR modeling, should be conducted to determine the valence state attribution of this spectral line. In the wavelength range of 290-475 nm, a total of 30 lines [21,22] have been reported. The dense distribution of spectral lines poses a considerable challenge in terms of line identification.…”

“…Over the decade, some efforts have been made in both theoretical calculations and experiments. Komatsu et al [21] and Era et al [22] provided a total of 30 spectral lines in the wavelength range of 290-475 nm using CoBIT-II and CoBIT, respectively. Murata et al [18] observed six more lines in the 580-850 nm range and identified two using the CI + all-order method.…”