Reasons for high charge collection efficiency of silicon detectors at HL-LHC fluences

Abstract

Position sensitive silicon detectors are more resilient to radiation then predicted from extensive measurements over the R&D phase for Large Hadron Collider. It was demonstrated over the past few years that they can be successfully operated also at the upgraded LHC (HL-LHC) and even beyond. A review of silicon properties affecting charge collection after irradiation will be given with special emphasis on their changes in very harsh radiation environments such as HL-LHC. Mainly three reasons: charge multiplication, high electric fields in undepleted bulk and saturation of trapping probabilities lead to better than expected performance of the silicon detectors. Initial acceptor removal, important for novel detector technologies such as Low Gain Avalanche Detectors and depleted CMOS sensors, will be also addressed.