High-precision mass measurements of $^{ 63}$Cu, $^{ 64-66}$Zn, $^{ 65}$Ga, $^{ 65-67}$Ge, $^{ 67}$As, $^{ 78,81}$Br, $^{ 80}$Rb, and $^{ 79}$Sr were performed utilizing a multireflection time-of-flight mass spectrograph combined with the gas-filled recoil ion separator GARIS-II. In the case of $^{ 65}$Ga, a mass uncertainty of 2.1 keV, corresponding to a relative precision of $\delta m / m = 3.5\times10^{ -8}$, was obtained and the mass value is in excellent agreement with the 2016 Atomic Mass Evaluation. For $^{ 67}$Ge and $^{ 81}$Br, where masses were previously deduced through indirect measurements, discrepancies with literature values were found. The feasibility of using this device for mass measurements of nuclides more neutron-deficient side, which have significant impact on the $rp$-process pathway, is discussed.
Categories: nucl-ex