ETD

• CMS
• pixel detector

This Master's thesis was carried out within the context of the CMS silicon pixel detector upgrade for the High-Luminosity Large Hadron Collider (HL-LHC). The increased collider luminosity will enable precise measurements in the Higgs boson sector and searches for beyond-the-Standard-Model (BSM) physics processes. The new CMS pixel detector is composed of three parts: a barrel (TBPX), a forward (TFPX), and an endcap (TEPX). This work focused on TBPX modules, that consist of one or two silicon pixel sensors, designed using planar or 3D columnar technologies, bump-bonded to two or four readout chips (ROCs). The first part of my thesis focused on the qualification and characterization of planar pixel modules through electrical tests conducted at the INFN Pisa and CERN laboratories. I also performed the energy calibration of the ROCs using quasi-monochromatic signals generated via X-ray Fluorescence (XRF). This measurement is crucial for effectively calibrating the reference ROC voltage units to the actual charge in electrons deposited by charged particles. The final part of the work evaluated the thermal performance of the TBPX mechanical structure. I conducted the first direct comparison between dummy and actual pixel module temperatures, validating their use in the thermal verification of the mechanical structure. Finally, I  performed thermal measurements on a quarter-section of the outermost TBPX layer to evaluate the temperature uniformity optimizing the thermal bridges.