The CMS electromagnetic calorimeter barrel upgrade for High-Luminosity LHC

16th International Conference on Calorimetry in High Energy Physics

Gras, Philippe^1

CEA/IRFU, Saclay, France^1

关键词: Electromagnetic calorimeter;    Front end electronics;    High Speed;    Integrated luminosity;    Lead tungstate crystal;    Operating temperature;    Radiation-induced;    Scintillation light;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/587/1/012016/pdf
DOI  :  10.1088/1742-6596/587/1/012016

来源: IOP

【 摘 要 】

The High Luminosity LHC (HL-LHC) will provide unprecedented instantaneous and integrated luminosity. The lead tungstate crystals forming the barrel part of the CMS Electromagnetic Calorimeter (ECAL) will still perform well, even after the expected 3000 fb-1at the end of HL-LHC. The scintillation light from the crystals is measured with avalanche photodiodes (APDs). Although the APDs will continue to be operational, there will be some increase in noise due to radiation-induced dark-currents. Triggering on electromagnetic objects with ∼140 pileup events necessitates a change of the front-end electronics. New developments in high-speed optical links will allow single-crystal readout at 40 MHz to upgraded off-detector processors, allowing maximum flexibility and enhanced triggering possibilities. The very-front- end system will also be upgraded, to provide improved rejection of anomalous signals in the APDs as well as to mitigate the increase in APD noise. We are also considering lowering the ECAL barrel operating temperature from 18°C to about 8 ∼10°C, in order to increase the scintillation light output and reduce the APD dark current.