First precision mass measurements of refractory fission fragments

Abstract

Atomic masses of Sr95-100, Zr98-105, and Mo102-110 have been measured with a precision of 10 keV employing a Penning trap setup at the IGISOL facility. Masses of Zr104,105 and Mo109,110 are measured for the first time. Our improved results indicate significant deviations from the previously published values deduced from beta end point measurements. The most neutron-rich studied isotopes are found to be significantly less bound (1 MeV) compared to the 2003 atomic mass evaluation. A strong correlation between nuclear deformation and the binding energy is observed in the two-neutron separation energy in all studied isotope chains. © 2006 The American Physical Society.