Electron - Ion Recombination Studies of Astrophysically Relevant Ions: Storage Ring and Electron Beam Ion Trap Based Measurements
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
This thesis contains experimental work that was performed at two state-of-the art devices for electron-ion collision physics, at a heavy-ion storage ring and at an Electron Beam Ion Trap. As a result, absolute recombination rate coefficients for H-like Si, He-like Si, Be-like Si, and Na-like Si, as well as Be-like Ne, Na-like S and Na-like Ar are reported over a wide energy range from μeV to keV. The experimentally derived recombination spectra are compared with results of Many Body Perturbation Theory calculations and AUTOSTRUCTURE calculations. Furthermore, the effect of external electric fields on the recombination rate is investigated for two Na-like ions, and a strong enhancement of dielectronic recombination into high Rydberg states is observed. Experimental plasma rate coefficients are derived for the studied ions for the first time and are compared with calculated values available in the literature. In the EBIT experiment, a novel extraction method provides complete charge state spectra of the ions for every extraction. Absolute DR rate coefficients for both H-like Si and He-like Si are obtained from the same measurement. Comparison with recorded X-ray spectra enables the separation of the photon spectra arising from charge-changing and charge-preserving reactions and facilitates the extraction of electron impact excitation rate coefficients.
Place, publisher, year, edition, pages
Stockholm: Department of Physics, Stockholm University , 2009. , 150 p.
atomic processes, electron-ion recombination, plasma
Research subject Physics
IdentifiersURN: urn:nbn:se:su:diva-33254ISBN: 978-91-7155-989-0OAI: oai:DiVA.org:su-33254DiVA: diva2:282779
2010-01-29, sal FB42, AlbaNova universitetscentrum, Roslagstullsbacken 21, Stockholm, 14:30 (English)
Zou, Yaming, Prof. Dr.
Schuch, Reinhold, Prof. Dr.
At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 6: Submitted. Paper 7: Submitted. 2010-01-072009-12-212010-01-08Bibliographically approved
List of papers