Characterization of Silicon Modules and Sensors for the ATLAS Inner Tracker Strip Detector

For the High-Luminosity LHC, the ATLAS Experiment will replace the current tracking system with an all-silicon detector, the Inner Tracker (ITk), consisting of inner pixel layers and outer strip layers. The ITk Strip Detector will operate in a much harsher environment than the current strip detector, the Semiconductor Tracker (SCT). For this reason, an intense R&D campaign has been completed to develop new radiation-hard sensors and front-end chips. In this work, test beam measurements performed to characterize ITk Strip prototype modules are presented. The performance of non-irradiated and irradiated modules is evaluated, with a focus on the hit detection efficiency, noise occupancy, and charge collection. The results prove that the current prototype modules will provide excellent performance for the entire lifetime of the High-Luminosity LHC. Based on the test beam results with ITk Strip prototype modules, sensors with a special layout were produced. These sensors consist of five zones with different aluminum layer and strip implant widths. Non-irradiated and irradiated sensors are characterized with electrical and test beam measurements. The results show that the implementation of a wide aluminum layer and strip implant mitigates some of the detrimental effects of radiation damage. The last part of this work deals with the Beam-Induced Background (BIB): particles generated by the interaction of the LHC beam with the surrounding environment. An online monitoring system developed to study the effects of the BIB in the SCT is described in detail.