The SiFi-CC detector for beam range monitoring in proton therapy -- characterization of components and a prototype detector module

Abstract

The following thesis presents research which constitutes the first steps towards the construction of a novel SiFi-CC detector intended for real-time monitoring of proton therapy. The detector construction will be based on inorganic scintillating fibers and silicon photomultipliers. The scope of the presented thesis includes the design optimization of the components of the proposed detector, as well as the construction, characterization, and tests of a prototype. The design optimization comprised an extensive systematic comparison of chosen inorganic scintillating materials, different types of scintillator surface modifications (wrappings and coatings), and different types of interface materials ensuring optical contact between the scintillators and the photodetector. The propagation of scintillating light in all investigated samples was described using two models: the exponential light attenuation model (ELA), and the exponential light attenuation model with light reflection (ELAR). The two models yielded the corresponding methods for energy and position reconstruction. Furthermore, the samples were investigated for energy and position resolution, light collection, and timing properties. Based on the results obtained from the optimization study, the detector prototype was constructed. Prototype tests were performed with two different photodetectors and data acquisition systems. The performance of the prototype was evaluated using the same metrics as in the case of single-fiber measurements. The best results were obtained in measurements with Philips Digital Photon Counting photosensor and the Hyperion platform, yielding a position resolution of 33.38 mm and an energy resolution of 7.73 %. The results obtained are satisfactory and sufficient for the successful operation of the proposed SiFi-CC detector.