Scintillation Light Detection and Application of Silicon Photomultipliers in Imaging Calorimetry and Positron Emission Tomography

This thesis deals with the weak light signals created in organic and inorganic scintillators, and their detection with silicon photomultipliers (SiPM). In this context, two fields of application are studied: hadron calorimetry, and the medical imaging technique of positron emission tomography. The result of a measurement of Birks’ coefficient kB is presented for the plastic scintillator tiles used in the analogue hadronic calorimeter prototype of the CALICE collaboration. The extracted kB is significantly larger compared to the default value used in previous Geant4 simulation studies. A new simulation method was developed which enables an improved description of the ionisation quenching effect. The impact on the simulated calorimeter response is demonstrated by means of a particle shower simulation study. A test environment was developed in order to pursue a complete SiPM characterisation, thus enabling a comparison of different SiPM types. The range of measurements covers the determination of the cross-talk and after-pulse corrected photon detection efficiency, and measurements of the spatial uniformity of single pixels. The characteristics of several different SiPM types and the derived qualification for different fields of application are discussed. In order to investigate the utility of SiPMs for the positron emission tomography application, a small-scale detector prototype was developed. First characterisation studies on the system are presented.