Electronic isotope shift factors for the Cu $4s \; ^2S_{1/2} - 4p \; ^2P^o_{3/2}$ line

TL;DR

This paper uses advanced relativistic calculations to determine isotope shift factors for the copper resonance line, revealing a correlation with transition energy and quantifying relativistic effects on recoil corrections.

Contribution

It introduces a detailed relativistic multiconfiguration approach to evaluate isotope shift factors for the Cu I resonance line, including the impact of relativistic recoil corrections.

Findings

Relativistic corrections reduce the transition mass factor by 5%.

A linear correlation between mass factors and transition energy was identified.

Extrapolation to observed frequencies is achieved through correlation models.

Abstract

State-of-the-art relativistic multiconfiguration Dirac-Hartree-Fock calculations have been performed to evaluate the electronic field and mass isotope shift factors of the Cu~I resonance line at $\lambda = 324.8$~nm. A linear correlation between the mass factors and the transition energy is found for elaborate correlation models, allowing extrapolation to the observed frequency limit. The relativistic corrections to the recoil operator reduces the transition mass factor by 5~\%.