Energies and lifetimes of the 9p and 10p excited states in atomic francium

TL;DR

This paper reports the first measurements of energies and lifetimes of specific excited states in atomic francium using CRIS, providing data to test relativistic atomic theory.

Contribution

It presents the first experimental data for high-n p-states in francium, validating relativistic coupled-cluster calculations.

Findings

Measured energies and lifetimes of 9p and 10p states in francium.

Good agreement with theoretical predictions for relative energies and lifetimes.

Identified a global offset in absolute energy measurements.

Abstract

We present the first measurement of 9p 2P1/2,3/2 and 10p 2P1/2,3/2 excited levels absolute wavenumbers and radiative lifetime in francium. We used the Collinear Resonance Ionization Spectroscopy (CRIS) technique, applied on a beam of 221Fr atoms. Prior to this work, no experimental data existed for francium p-states with n > 8. The results provide a precision experimental test of relativistic coupled-cluster theory for the heaviest alkali, showing good agreement for lifetimes and relative excitation energies, despite a residual global offset in absolute energies.