Intercombination Transitions in the n = 4 Shell of Zn-, Ga-, and Ge-Like Ions of Elements Kr through Xe

Abstract

Earlier beam-foil measurements have targeted 4s-4p intercombination transitions in the Zn-, Ga- and Ge-like ions of Nb (Z=41), Mo (Z=42), Rh (Z=44), Ag (Z=47) and I (Z=53). At the time, the spectra were calibrated with literature data on prominent lines in the Cu- and Zn-like ions. Corresponding literature data on the intercombination transitions in Ga- and Ge-like ions were largely lacking, which caused some ambiguity in the line identifications. We review the (mostly computational) progress made since. We find that a consistent set of state-of-the-art computations of Ga- and Ge-like ions would be highly desirable for revisiting the beam-foil data and the former line identifications for the elements from Kr (Z=36) to Xe (Z=54). We demonstrate that the literature data for these two isoelectronic sequences are insufficient, and we contribute reference computations in the process. We discuss the option of electron beam ion trap measurements as an alternative to the earlier use of classical light sources, beam-foil interaction and laser-produced plasmas, with the example of Xe (Z=54).

Electron impact excitation of Ge-like to Cu-like xenon ions in the extreme ultraviolet

“…These ions are of great interest for the next-generation fusion device ITER, as xenon can be used for cooling the edge plasma to reduce the heat load on the plasma-facing components by radiative cooling. Recently, in an extensive review by Träbert et al [7] they have emphasized the need of reliable atomic data computations of Gaand Ge-like ions to identify lines in the spectra observed in beam-foil measurements for the elements from Kr (Z = 36) to Xe (Z = 54). Ali and Nakamura [8] reported EUV spectroscopy measurements of highly charged xenon ions using electron beam ion trap (EBIT).…”

Electron Impact Excitation of Ge-like Te20+–Cd16+ Ions

“…Extreme ultraviolet (EUV) emissions from highly charged ions play an important role in the study of a wide variety of astrophysical and laboratory plasmas [1][2][3][4][5][6][7][8][9], particularly for laser-produced plasmas, fusion devices and electron beam ion traps (EBITs). The lines observed in the EUV spectra unveil information about plasma characteristics, viz., electron temperature, ion density and chemical composition.…”

“…In the present work, we aim to carry out a theoretical study of electron impact excitation of highly charged Ge-like Te 20+ , Sb 19+ , Sn 18+ , In 17+ and Cd 16+ ions. EUV emissions from highly charged tin ions in laser-produced plasma are used in state-of-the-art nanolithography [4,6,7]. Cd ions are of huge interest in Tokamak fusion research [5] like several other fifth row elements of the periodic table.…”