Photoionization cross sections of the 5S${}_{1/2}$ and 5P${}_{3/2}$ states of Rb in simultaneous magneto-optical trapping of Rb and Hg

TL;DR

This study measures the photoionization cross sections of specific rubidium states in a dual-species magneto-optical trap with mercury, providing key data for understanding ionization processes at particular wavelengths.

Contribution

The paper presents the first measurements of rubidium's photoionization cross sections at 253.7 nm and 401.5 nm in a combined Hg-Rb MOT, advancing knowledge of ionization dynamics in such systems.

Findings

Photoionization cross section of 5S1/2 state at 253.7 nm: ~1×10^{-20} cm^2

Photoionization cross section of 5P3/2 state at 253.7 nm: ~4.63×10^{-18} cm^2

Photoionization cross section of 5P3/2 state at 401.5 nm: ~1.18×10^{-17} cm^2

Abstract

We report the measurement of the photoionization cross sections of the 5S${}_{1/2}$ and 5P${}_{3/2}$ states of ${}^{87}$Rb in a two-species Hg and Rb magneto-optical trap (MOT) by the cooling laser for Hg. The photoionization cross sections of Rb in the 5S${}_{1/2}$ and 5P${}_{3/2}$ states at 253.7~nm are determined to be $1^{+4.3}_{-1}\times10^{-20}~\text{cm}^2$ and $4.63(30)\times 10^{-18}\text{cm}^2$, respectively. To measure the 5S${}_{1/2}$ and 5P${}_{3/2}$ states fractions in the MOT we detected photoionization rate of the 5P${}_{3/2}$ state by an additional 401.5~nm laser. The photoionization cross section of Rb in the 5P${}_{3/2}$ state at 401.5~nm is determined to be $\text{1.18(10)}\times10^{-17}~\text{cm}^2$.