Positron Emission Tomography (PET) is one of the most important molecular medical imaging techniques. Modern PET detectors are composed of individual modules, whose key component are light sensors such as the silicon photomultiplier (SiPM). Their efficiency, and especially their timing resolution, critically depend on temperature, making the cooling of detector modules essential. In this master’s thesis, simulations in Ansys Fluent are used to investigate the effectiveness of different cooling approaches. The influence of the thickness of ABS chip covers and of the ceramic layer between the PCB and the SiPM, vias within the PCB, and the volumetric flow rate in water cooling are evaluated. From the perspective of the position of the ground plane in the PCB, the presence of ceramic between the PCB and the SiPM, and the coupling or decoupling of vias with the ground plane, various geometries are compared. The effect of inlet water temperature is also examined. Furthermore, the temperature changes caused by the self-heating of the SiPM and the water flow layer material are evaluated. Finally, regarding the module’s contact with the surrounding air, the differences between conduction and convection at various heat transfer coefficients are presented.
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