Tutor: GERACI ANGELO Major Research topic
:Development of scintillation detectors based on silicon photomultipliers for high-energy gamma-ray applications
Advisor: FIORINI CARLO ETTOREAbstract:
The Dissertation represents a new challenge of Silicon PhotoMultiplier (SiPM) application to high-energy gamma-ray detection with scintillators in nuclear physics experiments and Prompt Gamma Imaging (PGI) in proton therapy. Although SiPMs are considered a promising alternative to the PhotoMultiplier Tubes (PMTs) in many medical imaging applications, more efforts are mandatory to introduce SiPM technology also into the field of high-energy gamma-ray detection (from tens of keV to tens of MeV). In this context, it is mandatory an optimization of the detector and the front-end electronics to face the wide energy range and to get high spectroscopic performances and imaging capability comparable to that measured with PMTs. Therefore, the thesis deals with the design, development and experimental validation of a multichannel SiPMs-based gamma-ray detection module of about 100 electronic channels which allows to read large LaBr3:Ce scintillators (1” x 1’’ and 2” x 2’’) for nuclear physics experiments, achieving both spectroscopic (measured energy resolution of 3.2% at 662 keV) and position sensitivity results in line with PMT standards and the best one within published results. Moreover, the photodetector was modified for PGI, proposing a pixelated structure of LYSO crystals which utilizes the multichannel readout developed earlier. The experimental results demonstrate that the designed photodetection module is suitable for prompt gammas detection in terms of spectroscopic performances, position sensitivity and energy range.