Design studies for the Phase II upgrade of the CMS Barrel Electromagnetic Calorimeter

The High Luminosity LHC (HL-LHC) aims to reach the unprecedented integrated luminosity of 3 ab^(−1) with an instantaneous luminosity up to 5 × 10^(34) cm^(−2) s^(−1). This poses stringent requirements on the radiation resistance of detector components and on the latency of the trigger system. The barrel region of the CMS Electromagnetic Calorimeter will be able to retain the current lead tungstate crystals and avalanche photo diode detectors which will meet the performance requirements throughout the operational lifetime of the HL-LHC. The new front-end electronics and very front-end system required at high luminosities will be described.