Licentiate Thesis: Photo-Recombination of Highly Charged Sulfur and Argon in R-EBIT

by Mr Safdar Ali (Stockholm University)

Friday 4 Mar 2011, 10:15 → 12:15 Europe/Stockholm

Atomic Physics meeting room, A4

This thesis contains experimental work on electron-ion collisions processes in highly charged ions, performed with the Stockholm Refrigerated Electron Beam Ion Trap (R-EBIT). We have obtained dielectronic recombination (DR) cross sections, resonant strengths and energy peak positions in H-like and He-like sulfur for the first time. These are compared with theoretical DR resonance strengths and energy positions, obtained with a distorted wave approximation approach. Furthermore, the experimentally obtained DR resonant strengths are used to check the behaviour of a scaling formula for lower Z, He-like iso-electronic sequence. Our results show a very good agreement with the trend obtained by previous measurements and verify the formula for lower Z ions. Moreover, photo-recombination of highly charged argon is also studied experimentally. We have obtained KLL DR peak positions for initially He- to B-like argon ions. The results are compared with the calculation and we found a pretty good agreement for He-, Li- and B-like ions. However, for Be-like argon we observe an energy shift of 9 eV between the experimentally obtained peak position and the calculated results.