Photoionization and Electron-Ion Recombination of Fe~XVII for High Temperature Plasmas

Earlier studies on electron-ion recombination of Fe~XVII, $e+ Fe~XVIII \rightarrow~Fe~XVII$, concentrated on low temperature region. However, due to its higher abundace, recombination in the high temperature region such as one exists in solar convection zone is of great importance. Total and level-specific recombination cross sections and rates of Fe~XVII are presented from the detailed study in the high temperature. The calculations were carried out using the unified method which incorporates both the radiative recombination (RR) and dielectronic recombination (DR) including the interference effects and provides self-consistent set of recombination rates and photoionization cross sections. The calculations included core excitations of levels n=2 and 3 complexes in contrast to earlier consideration of the n=2 levels only, and hence entails a large energy range and high temperature range. Resonances due to core excitations to n=3 levels are much more extensive and stronger than those to n=2 levels. These have introduced a broad and high FR peak at about 5$\times 10^6$ K.