Design and test of the Mu2e undoped CsI + SiPM crystal calorimeter
The Mu2e experiment at Fermilab will search for the charged-lepton flavour violating neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus. The calorimeter plays an important role in providing a fast trigger filter, excellent particle identification and a seeding for track reconstruction. Its requirements are to provide an energy (timing) resolution better than 10% (0.5 ns) and a position resolution below 1 cm, for 100 MeV electrons. The calorimeter consists of two disks, each one made of 674 un-doped CsI crystals readout by two large area arrays of 2 × 3 UV-extended SiPMs of 6 × 6 mm^2 dimensions. A large scale prototype (Module-0) has been constructed and tested with an electron beam in the energy range between 60 and 120 MeV at the BTF of Frascati National Laboratories. Results demonstrated that this calorimeter satisfies the Mu2e requirements.
© 2018 Published by Elsevier B.V. Received 28 June 2018, Revised 10 August 2018, Accepted 12 September 2018, Available online 22 September 2018.