Beta-delayed neutron emission from $^{94}$Rb at CARIBU

Beta-delayed neutron emission studies are important in the astrophysical r-process, nuclear structure and for nuclear reactor safety and design. The probability of $\beta$-delayed neutron emission in $^{94}$Sr is 10.2(2)\%. Many of the $\gamma$ rays in $^{94}$Sr are misplaced, and an estimated 26\% are thought to be missing. Recently [1], substantial $\gamma$ strength from above the neutron separation energy in $^{94}$Sr has been reported. An experiment to understand this high-lying $\gamma$ strength was performed with the X-Array (a high-efficiency HPGe clover array), SCANS (Small CLYC Array for Neutron Scattering) and the SATURN decay station (Scintillator And Tape Using Radioactive Nuclei) for $\gamma$, fast-neutron and $\beta$-particle detection, respectively. Data from $\beta$ decay of $^{94}$Rb ions delivered from CARIBU were collected in a triggerless digital data acquisition system, with detected $\beta$, n, and $\gamma$ events correlated offline. A new $^{94}$Sr level scheme will be presented, with confirmation of new levels and transitions, in addition to evidence of $\gamma$ strength above the neutron separation energy. [1] J. L. Tain et al, Phys. Rev. Lett 115 (062502) 2015.