Title :
Monitoring light source for CMS lead tungstate crystal calorimeter at LHC
Author :
Zhang, Liyuan Y. ; Zhu, Kejun J. ; Zhu, Ren-Yuan ; Liu, Duncan T.
Author_Institution :
California Inst. of Technol., Pasadena, CA, USA
fDate :
6/1/2001 12:00:00 AM
Abstract :
Light monitoring will serve as an intercalibration for Compact Muon Solenoid (CMS) lead tungstate crystals in situ at the Large Hadronic Collider, which is crucial for maintaining crystal calorimeter´s subpercent constant term in the energy resolution. This paper presents the design of the CMS electromagnetic calorimeter monitoring light source and high-level distribution system. The correlations between variations of the light output and the transmittance for the CMS choice of yttrium-doped PbWO4 crystals were investigated and were used to study monitoring linearity and sensitivity as a function of wavelength. The monitoring wavelength was determined so that a good linearity as well as adequate sensitivity can be achieved. The performance of a custom manufactured tunable laser system is presented. Issues related to monitoring precision are discussed
Keywords :
X-ray detection; calibration; lead compounds; particle calorimetry; solid scintillation detectors; yttrium; CMS crystal calorimeter; Compact Muon Solenoid; LHC; Large Hadronic Collider; PbWO4:Y; custom manufactured tunable laser system; electromagnetic calorimeter; high-level distribution system; intercalibration; light output variations; light source monitoring; linearity; monitoring precision; sensitivity; transmittance; Collision mitigation; Crystals; Energy resolution; Light sources; Linearity; Manufacturing; Mesons; Monitoring; Solenoids; Yttrium;
Journal_Title :
Nuclear Science, IEEE Transactions on
