Development of a power meter equipped target for ISOLDE RILIS

The resonance ionization laser ion source (RILIS) at the ISOLDE on-line isotope separator is based on the selective excitation of atomic transitions by tuneable laser radiation. RILIS has become more and more important and is today requested by the ISOLDE users for more than 50% of the time. Up to three independent laser beams are sent from the laser installation to the ISOLDE frontend where the target and ion source is mounted [1]. To monitor the beam position, a virtual reference point is generated inside the laser room by means of a quarts plate, mounted half way between laser table and ion source. A reflection from this surface allows monitoring the laser beam positions in the reference point

In-gas-jet laser spectroscopy of No 254 with JetRIS

International audienceHere we report online results with the in-gas-Jet Resonance Ionization Spectroscopy (JetRIS) apparatus. The S 0 1 ↔ P 1 1 transition of No 254 was successfully measured with sub-GHz resolution, marking a fivefold improvement over previous measurements. Recent developments in laser spectroscopy have allowed access to more exotic nuclei, but measurements of the heavy actinide region have been limited by line broadening mechanisms, limiting the precision with which nuclear properties can be deduced from the hyperfine spectrum. JetRIS provides a method to measure the heavy actinide region with a high level of sensitivity and higher resolution than previous experiments. The offline and online characterizations of the system are reported, and future perspectives are presented. Published by the American Physical Society 202

High-precision mass measurements of neutron deficient silver isotopes probe the robustness of the NN = 50 shell closure

International audienceHigh-precision mass measurements of exotic $^{95-97}$Ag isotopes close to the $N = Z$ line have been conducted with the JYFLTRAP double Penning trap mass spectrometer, with the silver ions produced using the recently commissioned inductively-heated hot cavity catcher laser ion source at the Ion Guide Isotope Separator On-Line facility. The atomic mass of $^{95}$Ag was directly determined for the first time. In addition, the atomic masses of $\beta$-decaying 2$^+$ and 8$^+$ states in $^{96}$Ag have been identified and measured for the first time, and the precision of the $^{97}$Ag mass has been improved. The newly measured masses, with a precision of $\approx$ 1 keV/c$^2$, have been used to investigate the $N =$ 50 neutron shell closure confirming it to be robust. Precise empirical shell-gap and pairing energies determined with the new ground-state mass data are used to benchmark state-of-the-art \textit{ab initio} calculations with various chiral effective field theory Hamiltonians. In addition, density functional theory (DFT) calculations and configuration-interaction shell-model (CISM) calculations are compared with the experimental results. All theoretical approaches face challenges to reproduce the trend of nuclear ground-state properties in the silver isotopic chain across the $N =$50 neutron shell and toward the proton drip-line. Furthermore, the precise determination of the isomeric excitation energy of $^{96m}$Ag serves as a benchmark for \textit{ab initio} predictions of nuclear properties beyond the ground state, specifically for odd-odd nuclei situated in proximity to the proton dripline below $^{100}$Sn