Compact electromagnetic calorimeters based on oriented scintillator crystals

Abstract Experimental results show that the strong crystalline field of a single-element crystal, e.g. Si or W, may lead to a huge decrease in the electromagnetic shower length, if the beam direction is aligned with the crystal axes. The same effect has been recently investigated in a high-Z crystal scintillator, i.e., a lead tungstate ( PbWO 4 ). The effect of shower length reduction can be exploited to develop an innovative type of electromagnetic calorimeter based on oriented scintillator crystals with the key feature of a reduced volume w.r.t. the state of the art. Here we present a Geant4 simulation study of e.m. shower length decreasing when a e ± ∕ γ beam is aligned with respect the PWO main crystal axes. The presented work opens the way for a variety of applications in high-energy physics and astrophysics. Such applications span from forward calorimeters/preshowers, to compact active beam dumps for light dark matter search, to pointing-strategy in satellite-borne gamma-ray telescope to decrease the required size to fully contain the e.m. shower generated by GeV to TeV particles for a point like source.