Analysis of Dielectronic Recombination Transitions for Highly Charged Iron Ions

The X-ray spectra emitted from highly charged Fe ions impacted by an electron beam with an energy ranging from 4.3 to 8.5 keV were measured in the Tokyo Electron Beam Ion Trap (EBIT). To analyze the observed spectra, cross sections for dielectronic recombination of KLn states were calculated for the range 4.3 ∼ 6.6 keV by the use of the distorted wave method. By comparing the convoluted cross sections with the experimental spectra, close agreement was obtained, and we identified He-like Fe as a dominant component (74%) in a mixture also containing Li-like ions (18%) and Be-like ions (8%). The ion density was estimated to be 6.5 ∼ 8.5 × 10 8 cm −3 .