p-process chaser detector in $n$-${\hat{I}}^3$ coincidences

Abstract

We propose two types of neutron-${\hat{I}}_1^3$-${\hat{I}}_2^3$ triple coincidence detectors (not constructed) to chase gamma transitions to produce p-nuclei following the neutron emission in the $({\hat{I}}^3,n)$ reaction. Neutrons are detected with 24 ${}^3$He counters embedded in a polyethylene moderator in Type I detector and with 6 liquid scintillation detectors in Type II detector, respectively. ${\hat{I}}^3$ rays are detected with two high-purity germanium detectors and four LaBr${}_3$(Ce) detectors. The detector which is referred to as p-process chaser detector is used to search for mediating states in ${}^{180}$Ta through which the isomeric and ground states in ${}^{180}$Ta are thermalized in the p-process. A search is made for both resonant states and unresolved states in high nuclear-level-density domain.