X-ray spectra of highly charged ions as measured in EBITs: Modelling and experiments

Description and modelling of ionized-matter environments requires large amounts of reliable atomic data on elementary atomic processes in ions. We report on X-ray spectra of highly charged tungsten and iridium ions measured employing the Electron-Beam Ion Trap (EBIT) at National Institute of Standards and Technology and the Main Magnetic Focus Ion Trap (MaMFIT) at Justus-Liebig Universität Gießen over the wide electron-beam energy ranges. The detailed modelling of the observed X-ray radiation spectra reveals the observed resonance series to originate from dielectronic-recombination processes involving transitions between 2ℓ - 3ℓ and 2ℓ - 4ℓ subshells in Na-like through Ar-like tungsten (NIST EBIT), and transitions between 2ℓ - 3ℓ subshells in K-like through Ni-like iridium (Giessen MaMFIT). In comparison to the NIST EBIT, which is the well established powerful and reliable tool for production and trapping of highly charged ions, the compact MaMFIT setup recently installed in Giessen reveals the capability to produce highly charged ions for plasma spectroscopy studies.