High-precision mass measurements of the ground and isomeric states in ${}^{124,125}$Ag

Abstract

The masses of the ground and isomeric states in ${}^{124,125}$Ag have been measured using the phase-imaging ion-cyclotron-resonance technique at the JYFLTRAP double Penning trap mass spectrometer. The ground states of ${}^{124}$Ag and ${}^{125}$Ag were found to be 30(250) keV and 250(430) keV less bound but 36 and 110 times more precise than in the Atomic Mass Evaluation 2020, respectively. The excitation energy of ${}^{124}$Ag${}^m$, $E_x=188.2(25)$ keV, was determined for the first time. The new precise mass values have been utilised to study the evolution of nuclear structure via two-neutron separation energies. The impact on the astrophysical rapid neutron capture process has been investigated via neutron-capture reaction rate calculations. The precision measurements indicate a more linear trend in two-neutron separation energies and reduce the mass-related uncertainties for the neutron-capture rate of ${}^{124}$Ag$(n,{\hat{I}}^3{)}^{125}$Ag by a factor of around 100. The new mass values also improve the mass of ${}^{123}$Pd, previously measured using ${}^{124}$Ag as a reference.

10 pages, 4 figures