Soft-X-ray spectra of highly charged Os, Bi, Th, and U ions in an electron beam ion trap

Abstract

Systematic variation of the electron-beam energy in an electron-beam ion trap has been employed to produce soft-X-ray spectra of Os, Bi, Th, and U with highest charge states ranging up to Ni-like ions. Guided by relativistic atomic structure calculations, the strongest lines have been identified with ∆n=0 (n=4 to n =4) transitions in Rb-to Cu-like ions. The rather weak 4p-4d transitions are much less affected by QED contributions than the dominant 4s-4p transitions. Our wavelength measurements consequently provide benchmarks with and (almost) without QED. Because the radiative corrections are not very sensitive to the number of electrons in the valence shell, our data, moreover, provide benchmarks for the evaluation of electron-electron interactions.Résumé francais: (traduit par le journal)

High-precision relativistic atomic structure calculations and the EBIT: Tests of quantum electrodynamics in highly charged ions

“…While QED corrections are expected to be small for high-l bound electrons as the centrifugal barrier l(l + 1)/2r 2 prevents them from getting too close to the nucleus, their contributions may not be negligible for heavy ions when comparing theory with experiment. Such is the case with the recent EBIT measurements that have produced highly accurate X-ray energies for the 4s-4p 3/2 transition in high-Z Cu-like ions [47][48][49] and, in particular, for the 4p 1/2 -4d 3/2 transition in Cu-like bismuth, thorium, and uranium [49]. RMBPT [34,50] and RCI [33] calculations were also carried out and were found to give essentially the same results.…”

“…Broken and continuous lines are frozen-and relaxed-core calculations [34]. Crosses with error bars are empirical data based on EBIT measurements [49]. periment.…”

Energy-Crossing and Its Effect on Lifetime of the 4 s 2 4 p 2 P 3/2 Level for Highly Charged Ga-Like Ions

“…[4] Radtke et al [5] measured the radiation from Ga-like tungsten ions. Träbert et al [6,7] studied the soft x-ray emission of highly charged Ga-like ions. Utter et al [8] recorded some of the energy levels and spectral lines of Ga-like W ions.…”

Atomic spectroscopy of trapped, highly charged, heavy ions

“…For example, the 4-4 resonance lines of the Cu and Zn-like ions have been followed up to uranium [8,9]. For the ions with a single valence shell electron (Cu sequence), the agreement with an extensive calculation that includes second order details of quantum electrodynamics (QED) is excellent.…”