Neutron response of PARIS phoswich detector

摘要

We have studied neutron response of PARIS phoswich [LaBr$_3$(Ce)-NaI(Tl)]detector which is being developed for measuring the high energy (E$_{\gamma}$ =5 - 30 MeV) $\gamma$ rays emitted from the decay of highly collective states inatomic nuclei. The relative neutron detection efficiency of LaBr$_3$(Ce) andNaI(Tl) crystal of the phoswich detector has been measured using thetime-of-flight (TOF) and pulse shape discrimination (PSD) technique in theenergy range of E$_n$ = 1 - 9 MeV and compared with the GEANT4 basedsimulations. It has been found that for E$_n$ $>$ 3 MeV, $\sim$ 95 \% ofneutrons have the primary interaction in the LaBr$_3$(Ce) crystal, indicatingthat a clear n-$\gamma$ separation can be achieved even at $\sim$15 cm flightpath.