High-resolution laser system for the S3-Low Energy Branch

Abstract

In this paper we present the first high-resolution laser spectroscopy results obtained at the GISELE laser laboratory of the GANIL-SPIRAL2 facility, in preparation for the first experiments with the S${}^3$-Low Energy Branch. Studies of neutron-deficient radioactive isotopes of erbium and tin represent the first physics cases to be studied at S${}^3$. The measured isotope-shift and hyperfine structure data are presented for stable isotopes of these elements. The erbium isotopes were studied using the $4f^{12}6s^2$ ${}^3{H}_6\to 4f^{12}{(}^{3}H)6s6p$ $J=5$ atomic transition (415 nm) and the tin isotopes were studied by the $5s^{2}5p^2{(}^3{P}_0)\to 5s^{2}5p6s{(}^3{P}_1)$ atomic transition (286.4 nm), and are used as a benchmark of the laser setup. Additionally, the tin isotopes were studied by the $5s^{2}5p6s{(}^3{P}_1)\to 5s^{2}5p6p{(}^3{P}_2)$ atomic transition (811.6 nm), for which new isotope-shift data was obtained and the corresponding field-shift $F_{812}$ and mass-shift $M_{812}$ factors are presented.