On-line Excited-State Laser Spectroscopy of Trapped Short-Lived Ra$^+$ Ions

TL;DR

This study performed on-line laser spectroscopy on short-lived radium ions to measure isotope shifts, hyperfine structures, and metastable state lifetime, aiding atomic parity violation research.

Contribution

It provides new experimental data on radium ion transitions, hyperfine structures, and state lifetimes crucial for atomic parity violation experiments.

Findings

Measured isotope shifts for specific transitions in Ra$^+$

Determined hyperfine structure constants in $^{213}$Ra$^+$

Established a lower limit for the metastable state's lifetime

Abstract

As an important step towards an atomic parity violation experiment in one single trapped Ra$^+$ ion, laser spectroscopy experiments were performed with on-line produced short-lived $^{212,213,214}$Ra$^+$ ions. The isotope shift of the $6\,^2$D$_{3/2}$\,-\,$7\,^2$P$_{1/2}$ and $6\,^2$D$_{3/2}$\,-\,$7\,^2$P$_{3/2}$ transitions and the hyperfine structure constant of the $7\,^2$S$_{1/2}$ and $6\,^2$D$_{3/2}$ states in $^{213}$Ra$^+$ were measured. These values provide a benchmark for the required atomic theory. A lower limit of $232(4)$ ms for the lifetime of the metastable $6\,^2$D$_{5/2}$ state was measured by optical shelving.