Mass measurements in the vicinity of the $\mathit{r} \mathit{p}$-process and the $\ensuremath{\nu} p$-process paths with the Penning trap facilities JYFLTRAP and SHIPTRAP

Mass measurements in the vicinity of the $r p$ -process and the $ν p$ -process paths with the Penning trap facilities JYFLTRAP and SHIPTRAP

C. Weber et al.

Phys. Rev. C 78, 054310 – Published 12 November 2008

Abstract

The masses of very neutron-deficient nuclides close to the astrophysical $r p$ - and $ν p$ -process paths have been determined with the Penning trap facilities JYFLTRAP at JYFL/Jyväskylä and SHIPTRAP at GSI/Darmstadt. Isotopes from yttrium ( $Z = 39$ ) to palladium ( $Z = 46$ ) have been produced in heavy-ion fusion-evaporation reactions. In total, 21 nuclides were studied, and almost half of the mass values were experimentally determined for the first time: ${}^{88}{Tc}$ , ${}^{90 - 92}{Ru}$ , ${}^{92 - 94}{Rh}$ , and ${}^{94, 95}{Pd}$ . For the ${}^{95}{Pd}$ $^{m}$ , ( $21 / 2^{+}$ ) high-spin state, a first direct mass determination was performed. Relative mass uncertainties of typically $δ m / m = 5 \times 10^{- 8}$ were obtained. The impact of the new mass values has been studied in $ν p$ -process nucleosynthesis calculations. The resulting reaction flow and the final abundances are compared with those obtained with the data of the Atomic Mass Evaluation 2003.