Orateur
Christian Faerber
Description
The LHCb calorimeter comprises the scintillator pad detector, preshower, electromagnetic Shashlyk type (ECAL) and hadronic Tile calorimeters, arranged in pseudo-projective geometry. All the four detectors follow the general principle of reading the light from scintillator tiles with wave-length shifting fibers, and transporting the light towards photomultipliers, all following the 25 ns readout. The calorimeter has been installed in the LHCb experiment, cabled and equipped with the front end electronics. The calorimeter has been pre-calibrated before installing in the pit, and the calibration techniques have been tested with the data taken in 2010.
The mission of the LHCb calorimeter system aims at selecting high E_T hadron, electron, photon and πo candidates for the first level trigger, providing electron identification essential for the flavor tagging, and giving access to studies of B-meson decays with πo or prompt photons.
Maximum expected annual dose acquired at the shower maximum position of the innermost ECAL cell amounts to 250 krad. The actual ECAL design assumes the possibility to replace the detector modules most subjected to the irradiation, so that the induced constant term of the energy resolution does not exceed 1.5%. Radiation resistance of the modules for the LHCb electromagnetic calorimeter was studied in order to optimize its design. The results of scintillating materials irradiation and the expected dose distribution map have been translated into the LHCb calorimeter performance degradation. Additional tests have been performed in highly radiative aera. Actual dose map at the LHCb calorimeter location for all the four calorimeter detectors and electronics will be monitored using sets of passive dosimeters, each comprising alanine, TLD and pin diode, and read out once per year.
The presentation addresses the LHCb calorimeter commissioning, expected performance, summary of the irradiation tests, expected radiation induced performance degradation and actual dose monitoring. This will be discussed in the context of the LHCb upgrade, taking place after 4-5 years of data taking. Foreseen operations and electronic for the LHCb upgrade will be discussed.
Auteur principal
Dr
Gaia Lanfranchi
(Laboratori Nazionali di Frascati - INFN)
