| dc.description.abstract | Proton CT has the potential to reduce range uncertainties in particle therapy planning. Proton CT gives a direct three-dimensional map of the stopping power of the tissue. This lowers the range uncertainties compared to conventional CT that requires a conversion from Hounsfield units to stopping power. The Bergen pCT collaboration is constructing a pCT prototype based on a high granularity digital tracking calorimeter. The high granularity is achieved using the ALPIDE sensor, which is a monolithic active pixel sensor. The ALPIDE sensor was developed for the ALICE experiment at CERN. In this thesis, experimental data from different setups with ALPIDE chips is analysed, with the goal of characterising the ALPIDE for use in the Bergen pCT prototype. The impact of different configuration parameters on the charge threshold and noise level of the ALPIDE, as well as the impact of charge threshold on cluster formation, are investigated to see how these parameters can be optimised for the pCT system. The microstructure of charged particle tracks in the ALPIDE is studied to see how the particles interact with the detector material on a micrometre scale. Long track structures in the sensitive layers of an electromagnetic calorimeter are studied, and associated energy spectra are compared to delta-electron spectra. Finally, lateral scans of ion beams are used to study the microstructure of helium and carbon ion tracks in an ALPIDE chip. | |
