The main objective of the OREO (ORiEnted calOrimeter) project is the construction of a new type of ultra-compact electromagnetic calorimeter consisting of an array of oriented scintillating crystals (PWO). In this calorimeter, the radiation length and consequently the electromagnetic shower are greatly reduced compared to the calorimeters currently used in high-energy and astroparticle physics.

This new type of ultra-compact (and ultra-fast) calorimeter can find applications in fixed-target experiments, beam dumps for the search of light dark matter (e.g., dark photon), or in the construction of satellite telescopes for high-sensitivity γ-ray detection with reduced dimensions (and costs).

The Ferrara group is tasked with designing and assembling the first layer of the calorimeter composed of oriented crystals. Additionally, Ferrara participates in high-energy electron beam tests at the beamlines extracted from the Super Proton Synchrotron at CERN, data analysis of the collected data, as well as Monte Carlo simulations of the prototype itself.