Installation and Commissioning of the On-Detector Electronics for the CMS Electromagnetic Crystal Calorimeter

The CMS electromagnetic barrel calorimeter is composed of 76,000 PbWO4 scintillating crystals. The scintillating light is captured by photodiodes, amplified and digitized. The conversion is performed inside the detector volume and data are transported through optical fibers to the off-detector electronics. About 25,000 Printed Circuit Boards of 5 different types and 5,500 Gigabit-Optical-Links and fibers should be installed and tested. The integration of electronics, cooling system, mechanical supports, low and high voltage distribution, synchronization and controls are discussed. Each step of the assembly sequence is followed by extensive test and quality control. Installation, commissioning strategy and the achieved system performance results are presented.