Measuring the branching ratios from the $y^8 {\rm P}_{9/2}$ state to metastable states in europium

TL;DR

This paper measures the branching ratios from an excited europium state to metastable states, providing data crucial for developing laser cooling techniques like Zeeman slowing and magneto-optical trapping.

Contribution

It offers the first precise measurement of branching ratios from the $y^8 P_{9/2}$ state in europium, informing the feasibility of laser cooling schemes.

Findings

Sum of branching ratios is approximately 1.05×10^{-3}.

Provides a scheme for Zeeman slowing and MOT using a metastable state.

Data supports the potential for laser cooling of europium atoms.

Abstract

We measure the branching ratios from the $y^8{\rm P}_{9/2}$ excited state to six metastable states of europium through fluorescence spectroscopy of an atomic beam. The sum of the six branching ratios is estimated to be $1.05(2)\times 10^{-3}$. This research provides us with insightful information to determine the feasibility of using the $a^8{\rm S}_{7/2} - y^8{\rm P}_{9/2}$ transition in order to implement the Zeeman slowing for europium atoms in the ground state. Based on this result, we also propose a scheme for Zeeman slowing and magneto-optical trapping, using a specific metastable state which has a cyclic transition.