## Electronic Theses and Dissertations

1993

Thesis

M.Sc.

Physics

Krause, L.,

Physics, Atomic.

CC BY-NC-ND 4.0

#### Abstract

Collisional transitions between Zeeman substates of Cs $\rm 6\sp2P\sb{1/2}$ atoms in collisions with He atoms have been investigated by methods of atomic fluorescence spectroscopy. Cs vapour contained in a quartz cell together with helium at low pressure, was selectively excited by pulsed dye-laser radiation to the $\rm 6\sp2P\sb{1/2,-1/2}$ Zeeman substate in a magnetic field of strength ranging from 1.5 T to 7 T. The fluorescence spectrum consisting of components emitted from the directly excited state and from the collisionally populated state, was resolved with a Fabry-Perot interferometer. Measurements of the relative intensities of the fluorescence components yielded the Zeeman mixing cross section for Cs-He collisions. It was found that the enhancement in the cross section varied as B$\sp2$ in the range 0  5 T. A theoretical calculation of the magnetic-field enhancement of the cross section was also carried out, using time-dependent perturbation theory. The results of the calculation are in very good agreement with the experimental results at fields in the range 0 $<$ B $<$ 5 T, though not beyond 5 T where further theoretical work remains to be done.Dept. of Physics. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1993 .G365. Source: Masters Abstracts International, Volume: 32-02, page: 0636. Adviser: L. Krause. Thesis (M.Sc.)--University of Windsor (Canada), 1993.

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