MOT-based Lifetime Measurements of Potassium-39 5p1/2 and 5p3/2 States

Author (Your Name)

Huan Q. Bui, Colby CollegeFollow

Date of Award

2021

Document Type

Honors Thesis (Open Access)

Department

Colby College. Physics and Astronomy Dept.

Advisor(s)

Charles Conover

Abstract

This thesis presents measurements of the lifetimes of 5p1/2 and 5p3/2 of K39 via exciting a cloud of K39 atoms in a magneto-optical trap by a linearly-polarized pulse of 405 nm light followed polarization-specific, time-resolved fluorescence detection. We find that $\tau_{5p1/2} = $ 138.8 $\pm$ 1.6 ns, which is consistent with past measurements \cite{triumf}, \cite{berends} and calculations \cite{safranova}. The $\tau_{5p3/2}$ measurement is naturally more involved since quantum beats due to hyperfine and Zeeman effect are present. Our observation of $\tau_{5p3/2} =$ 137.6 $\pm$ 3.1 ns and $\tau_{5p3/2} =$ 136.0 $\pm$ 2.4 ns, obtained from two slightly different approaches, are compared against past measurements \cite{berends}, \cite{Svanberg_1971}, \cite{Ney1969}, \cite{schmeider} and theoretical calculations in \cite{safranova}. We determine that future work is needed to reduce the uncertainty in our measurement and resolve the discrepancy in the literature.

Keywords

lifetime measurements, single-photon counting, magneto-optical trap, quantum beats, hyperfine structure, Zeeman effect

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