Seminar Details

Investigation of Resonant Recombination Processes on Highly Charged Silicon in an EBIT

Thomas Baumann, Max Planck Institute for Nuclear Physics
Friday, February 1, 11:00 AM - Special Seminar
NSCL Lecture Hall

Spectroscopic studies of inter-shell (K-L) resonant electronic recombination processes for He-like to O-like Si ions (Si12+ to Si6+) are presented and compared to theoretical predictions obtained from MCDF and FAC calculations. These measurements were performed at the new cryogenic electron beam ion trap of the MPIK. The charge state evolution and charge-breeding process in this machine was further studied using the time resolved evolution of the resonant recombination spectra. Strong contributions of higher-order recombination processes (trielectronic recombination, TR) are compared to lines resulting from first order dielectronic recombination (DR) using the strength ratio. For C-like Si, the measured strength ratio 1.2 +- 0.1 is about half the theoretical value. This deviation can be explained by barely resolvable contributions from long-lived metastable states in the recombining C-like ions.