High-precision mass measurements and production of neutron-deficient isotopes using heavy-ion beams at IGISOL

Abstract

An upgraded ion-guide system for the production of neutron-deficient isotopes with heavy-ion beams has been commissioned at the IGISOL facility with an Ar-36 beam on a Ni-nat target. It was used together with the JYFLTRAP double Penning trap to measure the masses of Zr-82, Nb-84, Mo-86, Tc-88, and Ru-89 ground states and the isomeric state Tc-88(m). Of these, Ru-89 and Tc-88(m) weremeasured for the first time. The precision of measurements of Zr-82, Nb-84, and Tc-88 was significantly improved. The literature value for Mo-86 was verified. The measured states in Tc-88 were compared to shell-model calculations and additional constraints on the spins and level scheme were obtained. The masses of Mo-82 and Ru-86 have been predicted using the measured masses of their mirror partners and theoretical mirror displacement energies, resulting in more tightly bound nuclei with smaller atomic mass uncertainties than reported in the literature.