A High Resolution Phoswich Detector: $LaBr3(Ce)$ Coupled With $LaCl3(Ce)$

An innovative solution for the forward end‐cap CALIFA calorimeter of $R3B$ is under investigation consisting of two scintillation crystals, $LaBr3$ and $LaCl3,$ stacked together in a phoswich configuration with one readout only. This dispositive should be capable of a good determination of the energy of protons and gamma radiation. This composite detector allows to deduce the initial energy of charged particles by $ΔE1+ΔE2$ identification. For gammas, the simulations show that there is a high probability that the first interaction occurs inside the scintillator at few centimeters, with a second layer, the rest of the energy is absorbed, or it can be used as veto event in case of no deposition in the first layer. One such a detector has been tested at the Centro de MicroAnálisis de Materiales (CMAM) in Madrid. Good resolution and time signal separation have been achieved.