High-Energy Photon Detection With LYSO Crystals

For the first time, the response function to high-energy photons of a 3times3 matrix comprising large volume LYSO crystals was measured using energy marked photons provided by the tagged photon facility of MAMI. The crystal quality was determined based on the optical transparency, the intrinsic radioactivity and the luminescence yield. Energy and time resolutions for photons up to 490 MeV photon energy have been deduced from the reconstruction of the electromagnetic shower deposited into the crystal array and the data deliver very promising results.