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 Ar36 beam on a Ninat target. It was used together with the JYFLTRAP double Penning trap to measure the masses of Zr82, Nb84, Mo86, Tc88, and Ru89 ground states and the isomeric state Tcm88. Of these, Ru89 and Tcm88 were measured for the first time. The precision of measurements of Zr82, Nb84, and Tc88 was significantly improved. The literature value for Mo86 was verified. The measured states in Tc88 were compared to shell-model calculations and additional constraints on the spins and level scheme were obtained. The masses of Mo82 and Ru86 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.