Direct mass measurements of proton-rich isotopes of Ge, As, Se, and Br

Abstract

The masses of neutron-deficient nuclei close to the proton drip line are an important input for the rapid proton-capture process modeling above ${}^{56}\mathrm{Ni}.$ The measurement of the masses of proton-rich nuclei with $32l~Zl~35$ has been made using a direct time-of-flight technique. The masses of the nuclides ${}^{66}\mathrm{As}{,}^{68}\mathrm{Se},$ and ${}^{71}\mathrm{Br}$ are reported for the first time, with mass excesses of $\ensuremath{-}51500(680),$ $\ensuremath{-}53620(1000),$ and $\ensuremath{-}57060(570) \mathrm{keV}$ being found. The masses agree well in most cases with the Audi-Wapstra systematics.