X-ray spectral measurements and collisional radiative modeling of Ni- to Kr-like Au ions in electron beam ion trap plasmas

Abstract

The line emission of $n=\stackrel{\ensuremath{\rightarrow}}{7}3,$ $\stackrel{\ensuremath{\rightarrow}}{6}3,$ $\stackrel{\ensuremath{\rightarrow}}{5}3,$ and $\stackrel{\ensuremath{\rightarrow}}{4}3$ transitions in Ni- to Kr-like gold ions produced in the Livermore electron beam ion traps EBIT-I and EBIT-II has been recorded with an x-ray crystal spectrometer and a photometrically calibrated microcalorimeter. The plasmas had either monoenergetic electron beams with ${E}_{\mathrm{beam}}=2.66,$ 3.53, or 4.54 keV or an experimentally simulated thermal electron distributions with ${T}_{\mathrm{e}}=2.5\mathrm{keV}.$ The electron densities were $\ensuremath{\approx}{10}^{12}{\mathrm{cm}}^{\ensuremath{-}3}.$ The measured spectra have been compared to atomic structure calculations and synthetic spectra provided by the Hebrew University Lawrence Livermore Atomic Code atomic data package. Line identifications and accurate photon energy measurements have been made for many collisionally excited transitions. Approximately 140 lines have been identified in nine charge states. Agreement within 20--30 % exists between the measured and modeled line intensities for most lines excited by the monoenergetic electron beam plasmas, although some larger discrepancies can be found for some weaker features.