• Tracker
• Silicon
• Detector
• Pixel
• CMS
• RD53A
• Phase-2
• Simulation
• Synopsys
• Inner

The purpose of this thesis is to study the new silicon pixel sensors that will be used for the upgrade of the CMS experiment at the high luminosity phase of the HL-LHC. In order to face the new challenges, the current pixel design has to be improved: the pixel elementary cell is designed with reduced size and the innovative technologies, more radiation tolerant, of thin planar and 3D columnar pixels have to be used. The challenge of building the new pixel detector is therefore exciting, and the CMS collaboration will soon have to select the most robust and high-performance design. My thesis work is part of this research program and is focused on the study of planar and 3D detectors, through simulations, laboratory measurements, and beam tests of detector prototypes. The simulated pixel devices have the same design features as the prototypes currently under investigation in CMS. Results are shown for the detector operation and the signal provided by MIP particles passing through the active volume. The degradation of the sensor's performance by the radiation damage has then been evaluated by the implementation of a specific radiation damage model inside the Synopsys code. Test Beam experiments allow the evaluation of tracking performance with readout electronics and data acquisition systems similar to the final experiment implementations. The main study and results achieved are on the cluster and position resolution for detectors with different pixel design choices. In the cleanroom at INFN Pisa I have worked on the test setup assembly and the quality assurance of 3D columnar and planar pixel devices both assembled on a readout chip. Evaluation of the noise and the functionality of each pixel have been studied by using beta source.