Title :
Monitoring light source for CMS lead tungstate crystal calorimeter at LHC
Author :
Zhang, Liyuan ; Kejun Zhu ; Ren-yuan Zhu ; Liu, Duncan
Author_Institution :
California Inst. of Technol., Pasadena, CA, USA
Abstract :
Light monitoring will serve as an inter calibration for the CMS lead tungstate crystals in situ at LHC, which is crucial for maintaining the crystal calorimeter´s sub percent constant term in energy resolution. This paper presents the design of the CMS ECAL monitoring light source and high level distribution system. The correlations between variations of the light output and the transmittance for the CMS choice of Y doped PbWO4 crystals were investigated, and were used to study monitoring linearity and sensitivity as a function of the 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 :
calorimeters; particle calorimetry; solid scintillation detectors; CMS; PbWO4 calorimeter; PbWO4:Y; energy resolution; light monitoring; light output; linearity; monitoring light source; monitoring linearity; monitoring precision; monitoring sensitivity; monitoring wavelength; transmittance; tunable laser; Calibration; Collision mitigation; Crystals; Energy resolution; Large Hadron Collider; Light sources; Linearity; Manufacturing; Monitoring; Tunable circuits and devices;
Conference_Titel :
Nuclear Science Symposium Conference Record, 2000 IEEE
Conference_Location :
Lyon
Print_ISBN :
0-7803-6503-8
DOI :
10.1109/NSSMIC.2000.949184
