Speaker
Dr
Ivano Sarra
(LNF INFN Frascati, Italy)
Description
The Mu2e experiment at FNAL aims to measure the charged-lepton flavor violating
neutrinoless conversion of of a negative muon into an electron. The conversion
results in a monochromatic electron with an energy slightly below the rest mass
of the muon (104.97 MeV). The calorimeter should confirm that the candidates
reconstructed by the extremely precise tracker system are indeed conversion
electrons. We therefore look for a calorimeter with a large acceptance, good energy
resolution O(5%) and a reasonable position (time) resolution of ~0.5 cm (<0.5ns).
Moreover, the calorimeter should also provide a trigger for the experiment and
perform a powerful mu/e particle identification. Finally, it should be able to keep
functionality in an environment where the background delivers a dose of
~ 200 Gy/year in the hottest area. It will also need to work immersed in
1 T axial magnetic field. The baseline version of the Mu2e calorimeter is
composed by two disks, 11 cm wide, of inner (outer)radius of 360 (670) mm
filled by ~ 1800 hexagonal LYSO crystals. Each crystal is readout by two
large area APDs. At the moment of writing, due to the increasing cost of the
LYSO, we are examing cheaper alternative based on BaF2 or pure CsI
crystals. We will report the tests done, at a dedicated cosmic rays test,
with our medium size prototype that is constituted by 16 square LYSO
crystals of 3x3x13 cm**3 read out by Hamamatsu APDs and
dedicated prototypes of the Front End electronics. We will report also
on the first tests done with single BaF2 and pure CsI crystals when
readout by means of large area UV extended APD or SiPM.
Primary author
Dr
Ivano Sarra
(LNF INFN Frascati, Italy)
