CEPA: A LaBr3(Ce)/LaCl3(Ce) phoswich array for simultaneous detection of protons and gamma radiation emitted in reactions at relativistic energies

A prototype CEPA4, made of four optically isolated phoswich-crystals of LaBr3(Ce)+LaCl3(Ce) packed together in one can of Al, was tested with high energy protons (70-230 MeV) at the cyclotron of Krakow. Further, the response to different gamma radiation standard sources and cosmic muons was determined. Shape analysis of the pulses derived from the four individually coupled PM-tubes was performed and were used as input functions for Monte Carlo simulations in order to simulate the efficiencies and resolutions of a final detector design consisting of 750 such phoswich crystals arranged in a cylindrical disc