Half-life ($T_{1/2}$) and β-delayed neutron branching ($P_n$) values of 492(25) ms and 49(8)$\%$, 350(15) ms and 72(8)$\%$, and 93(13) ms and 90(10)$\%$ for the $r$-process nuclei ${}^{137,138,139}$Sb, respectively, have been measured at the CERN On-Line Isotope Mass Separator (ISOLDE) facility by counting β-delayed neutrons. More precise $T_{1/2}$ and $P_n$ values of 300(15) ms and 27(4)$\%$, and 273(7) ms and 50(8)$\%$ for ${}^{136,137}$Sn, respectively, have also been measured. The sources were prepared by using the selective ionization of Sb or Sn with the Resonance Ionization Laser Ion Source and the high-resolution mass separator. The new data for Sb isotopes are compared with calculated $T_{1/2}$ and $P_n$ values for both spherical and nonspherical shapes. The data have been incorporated into parametrized nucleosynthesis calculations of the $r$ process in high-entropy winds of core-collapse supernovae in order to study the properties of the $A$ $=$ 130 solar-system $r$-process abundance peak.

• Received 22 September 2011

DOI:https://doi.org/10.1103/PhysRevC.84.061307