Title :
The design of the cooling system for the CMS Barrel Electromagnetic Calorimeter
Author_Institution :
PH-CMA group, CERN, Geneva
fDate :
Oct. 29 2006-Nov. 1 2006
Abstract :
CMS is one of the four experiments being constructed for the LHC. The electromagnetic calorimeter (ECAL) is made of lead tungstate (PbWO4) crystals. Scintillation light from the crystals in the barrel is detected by avalanche photo diodes (APD). The number of scintillation photons emitted by the crystals and the amplification of the APD are both temperature dependent. Keeping the constant term of the energy resolution (the contribution to the fractional energy resolution which is independent of energy) below a few tenths of percent requires the temperature of crystals and APDs to be stabilized to within 0.057 K. In this contribution, we describe the innovative solutions which have been developed and implemented to achieve this performance.
Keywords :
cooling; particle calorimetry; solid scintillation detectors; CMS barrel electromagnetic calorimeter; Compact Muon Solenoid; LHC; Large Hadron Collider; PbWO4; avalanche photodiodes; lead tungstate; Collision mitigation; Detectors; Electronics cooling; Energy resolution; Large Hadron Collider; Lead; Photonic crystals; Samarium; Temperature sensors; Thermal stability;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2006. IEEE
Conference_Location :
San Diego, CA
Print_ISBN :
1-4244-0560-2
Electronic_ISBN :
1095-7863
DOI :
10.1109/NSSMIC.2006.356190
