Spectroscopic Study and Lifetime Measurement of the $6d7p$ $ ^{3}F_{2}^{o}$ state of radium

TL;DR

This study introduces a novel spectroscopic method for precisely measuring oscillator strengths, branching ratios, and the lifetime of a specific excited state in radium without needing atom count, providing valuable atomic data.

Contribution

A new measurement technique for oscillator strengths and lifetimes in radium that avoids the need for atom number knowledge and improves data accuracy.

Findings

Measured oscillator strengths and branching ratios for radium's $6d7p$ $^3F_2$ state.

Constrained the branching ratio to the $^3D_3$ state to less than 0.4%.

Determined the lifetime of the $^3F_2$ state as 15 ± 4 ns.

Abstract

We report a method for the precision measurement of the oscillator strengths and the branching ratios of the decay channels of the $6d7p$ $^3F_2$ state in $^{226}$Ra. This method exploits a set of metastable states present in Ra, allowing a measurement of the oscillator strengths that does not require knowledge of the number of atoms in the atomic beam. We measure the oscillator strengths and the branching ratios for decays to the $7s6d$ $^3D_1$, $7s6d$ $^3D_2$, and $7s6d$ $^1D_2$ states and constrain the branching ratio to the $7s6d$ $^3D_3$ state to be less than 0.4$\%$ (68$\%$ confidence limit). The lifetime of the $^3F_2$ state is determined to be $15 \pm 4$ ns.