Dörfler, Alexander. Cold molecular ionneutral collisions in a dynamic ionatom hybrid trap. 2019, Doctoral Thesis, University of Basel, Faculty of Science.

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Official URL: http://edoc.unibas.ch/diss/DissB_13518
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Abstract
This thesis explores the fundamental physical and chemical processes between molecular ions and neutral atoms in the gas phase at very low energies. At temperatures in the mK regime, these are dominated by longrange interactions and only a few partial waves. This study contributes to the understanding of the details of intermolecular interactions and provides valuable data for benchmarking theoretical models and quantumchemical calculations. Although there is a wide range of previous atomic collision system studies, the investigations of cold collisions with molecular ions are limited. The experimental setup used in this work enabled the measurement of rate coefficients for molecular ionneutral collisions. The development of a dynamic ionneutral hybrid trap with improved control over collision energy led to new insights into chargetransfer rate coefficients for molecular ionneutral atom collisions involving N$^+_2$+Rb, O$^+_2$+Rb and N$_2$H$^+$+Rb. Two different experimental settings enable stateand collisionenergy dependent measurements of rate coefficients for all systems revealing an intriguing interplay between longand shortrange effects for the homonuclear diatomics by comparison to theoretical calculations and surprising experimental results for the polyatomic study. A fit of a constant function to the measured CT rate coefficients in the statedependent experiment of N$_2$H$^+$+Rb yielded the similar result as for N$^+_2$+Rb($5s$)($^2S_{1/2}$). In the collisionenergy dependent experiment the CT rate coefficient for N$_2$H$^+$+Rb($5s$)($^2S_{1/2}$) and N$_2$H$^+$+Rb($5p$)($^2P_{3/2}$) are both similar to the results for N$^+_2$+Rb($5s$)($^2S_{1/2}$), and also the rate coefficients increase as the collisionenergy increases.
Advisors:  Willitsch, Stefan and Dulieu, Olivier 

Faculties and Departments:  05 Faculty of Science > Departement Chemie > Chemie > Chemische Physik (Willitsch) 
UniBasel Contributors:  Dörfler, Alexander and Willitsch, Stefan 
Item Type:  Thesis 
Thesis Subtype:  Doctoral Thesis 
Thesis no:  13518 
Thesis status:  Complete 
Number of Pages:  1 OnlineRessource (xi, 131 Seiten) 
Language:  English 
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Last Modified:  04 Mar 2020 05:30 
Deposited On:  03 Mar 2020 13:47 
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