Equilibrium and dynamis studies of the van der Waals molecule titanium-helium: TiHe
Authors
Quiros-Aguilar, Nancy P.
Issue Date
2016
Type
Dissertation
Language
Keywords
Cold chemistry , Cold molecules , TiHe , van der Waals molecules
Alternative Title
Abstract
Atoms that are weakly bound by the van der Waals (vdW) interaction are called van der Waals molecules. Conditions for the existence and formation of vdW molecules are favorable at low temperatures due to their weak binding energy. In the experiment described in this thesis, we used laser ablation and He buffer gas cooling to form the exotic vdW molecule titanium-helium: TiHe. A spectroscopic search for the TiHe molecule was initially conducted near the a 3F2 → y 3F2 atomic Ti transition at 25107.410 cm-1. Several laser-induced-fluorescence signals were found and studied. However, it was not possible to conclude that these peaks corresponded to a bound TiHe molecule. We continued the search for TiHe and multiple transitions were found closely blue detuned from the a 3F2 → y 3F3 atomic Ti transition at 25227.220 cm-1. Measurements of the TiHe binding energy were obtained from the study of its equilibrium thermodynamic properties and good agreement with theoretical predictions for the molecule's binding energy was obtained. The creation of the TiHe molecule is of great significance, since TiHe has interesting properties: TiHe possesses an anisotropic interaction due to its non zero angular momentum and it is the first neutral molecule characterized by the Hund's case e).We believe that TiHe was formed from the constituent cold atoms through three body recombination. Progress towards measuring the three body recombination rate coefficient K3 will be discussed and preliminary values of this coefficient will be shown.
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In Copyright(All Rights Reserved)