Date Thesis Awarded

5-2020

Document Type

Honors Thesis

Degree Name

Bachelors of Science (BS)

Department

Physics

Advisor

Todd Averett

Committee Members

Paul Davies

Kieth Griffioen

Abstract

3He is an isotope of helium whose nucleus is composed of two protons and one neutron. The proportion of atoms whose spins are pointed along the same direction in a volume of 3He gas is known as the polarization. This study entails two experiments in the field of 3He polarimetry concerned with measuring the polarization of a 3He cell and reducing the uncertainty associated with it. 3He cells are full of gaseous 3He, along with alkali metal vapors, K and Rb in our case. The polarization of a 3He cell can be measured using an electron paramagnetic resonance (EPR) frequency shift. The EPR frequency is related to the 3He polarization through a constant, Ko. The first experiment in this study involves isolating Ko by varying the geometry of the magnetic field generated by the polarized 3He. The spatial dependence of the polarization is also of interest. To measure this, we use Faraday rotation. For a 3He cell, the amount of rotation is determined by the polarization of the alkali gas. The second experiment in the study involves inferring the polarization of a path through a cell using Faraday rotation measurements. This will establish a spatial mapping of polarization in the cell that will help improve our understanding of its overall polarization.

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