PERFORMANCE OF VANDLE MEASURING BETA-DELAYED NEUTRON SPECTRA OF FISSION FRAGMENTS

摘要

Beta-delayed neutron spectra and branching ratios of fission-fragment nuclei can constrain nuclear-structure models far from stability and inform r-process abundances. The Versatile Array of Neutron Detectors at Low Energy (VANDLE)[1] was commissioned to study the beta-delayed neutron emission spectra of over 30 fission-fragments for the first time. The experiment was performed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Lab and included nuclei near ~(78)Ni and ~(132)Sn; and some within possible r-process paths. A complete set of 48 smaller (60 cm) VANDLE modules were arranged in a cylinder about the tape-driven implantation point, with two high purity Ge clovers for gamma-ray coincidence measurements. Details of the experiment, performance of the VANDLE decay station,and preliminary analysis will be presented.