Abstract :
The electromagnetic calorimeter of CMS at the Large Hadron Collider (LHC) has been designed to measure the energy of electrons and photons with high resolution over a wide energy range. The detector consists of 61200 PBWO4 crystals for the barrel and 14648 crystals for the endcaps, with a pseudo-rapidity coverage of |eta|les3.0. Preshower detectors are located in front of each endcap. The calorimeter has a pseudo-projective geometry. Great care has been taken in its design to minimize the effects of gaps and cracks in order to ensure the required energy resolution. The detector will operate in a magnetic field of 4 Tesla, and with a bunch crossing rate of 40 MHz. This requires fast and radiation hard crystals, photo-detectors and read-out electronics. An overview of the design, and the status of the construction, will be presented with special consideration given to the challenging goals
Keywords :
avalanche photodiodes; electron detection; gamma-ray detection; particle calorimetry; photodetectors; position sensitive particle detectors; readout electronics; scintillation counters; 14648 crystals; 61200 PBWO4 crystals; Avalanche photodiodes; CMS; LHC; bunch crossing rate; compact muon solenoid; electromagnetic calorimeter; electron energy measurement; elementary particles; energy resolution; large hadron collider; magnetic field; photodetectors; photon energy measurement; preshower detectors; pseudoprojective geometry; pseudorapidity coverage; radiation detectors; radiation hard crystals; read-out electronics; scintillation detectors; Collision mitigation; Detectors; Electromagnetic measurements; Electrons; Energy measurement; Energy resolution; Geometry; Large Hadron Collider; Photon collider; Photonic crystals; Avalanche photodiodes; calorimetry; crystals; detectors; elementary particles; energy measurement; photodetectors; radiation detectors; scintillation detectors;