The LHCb collaboration, dedicated to studying CP violation in B-meson decays at CERN’s Large Hadron Collider (LHC), has received the first components of its calorimeter system from Russia. The first 1200 of 3300 electromagnetic calorimeter (ECAL) modules and the first two of 52 hadron calorimeter (HCAL) modules were delivered to CERN in September. The so-called shashlik-type (lead-scintillator sandwich) ECAL modules are being produced by Russia’s Institute for Theoretical and Experimental Physics in collaboration with CERN. The HCAL tile calorimeter is the responsibility of the Institute of High Energy Physics in Protvino, with contributions from the Horia Hulubei National Institute for Physics and Nuclear Engineering in Bucharest, Romania; the Institute of Physics and Technologies in Kharkiv, Ukraine; and CERN. Series production of a Preshower detector is under preparation at the Institute for Nuclear Research in Moscow. The fast 40 MHz calorimeter detector readout electronics are the responsibility of French (Annecy, LAL-Orsay and Clermont-Ferrand) and Spanish (Barcelona) LHCb groups.
LHCb’s calorimeter has been designed for speed, since it will be used for triggering on collisions arising from the LHC’s 40 MHz bunch crossing rate. All three sub-detectors (Preshower, ECAL and HCAL) are based on fast scintillators with wavelength-shifting fibre readout. The HCAL (which will be used exclusively for triggering) uses iron as its passive medium, while the ECAL uses lead. While also participating in the trigger, another important function of the ECAL will be to reconstruct neutral pions and photons from B-meson decays. Production is set to continue at a rate of 10 ECAL modules per day and one HCAL module every two weeks.
