Mass measurements of neutron-rich Rh isotopes using the Canadian Penning Trap

The Canadian Penning Trap (CPT) has been at the Argonne National Laboratory's CARIBU facility for over a decade, where it measured the masses of over 300 nuclei produced from the spontaneous fission of CARIBU’s ²⁵²Cf source. The current phase-imaging ion-cyclotron-resonance technique adopted by the CPT provides a typical precision of 1-10 keV/c². With such precision, not only atomic masses can be measured to high precision, but also the energy difference between the nuclear ground state and certain nuclear isomer. Recently, a series of mass measurement campaigns were carried out using the CPT to measure the masses of importance for understanding the astrophysical rapid neutron capture process (r process), to improve precision on certain nuclear masses which largely depend on beta end point measurements, or to probe the ground state and the isomer(s) mass for the purpose of nuclear structure or nuclear astrophysics study. These measurements include neutron-rich odd-odd ^{108,110,112,114,116}Rh isotopes, which were known to present long-lived isomeric states (of unknown energy) based on lifetime measurements. We will present the most precise measurements to date, done at sufficient precision to resolve some of the isomers for the first time as well as unveil possible unknown isomers.