The PRIMA (PRoton IMAging) collaboration: Development of a proton Computed Tomography apparatus

This paper describes the development of a proton Computed Tomography (pCT) apparatus able to reconstruct a map of stopping power useful for accurate proton therapy treatment planning and patient positioning. This system is based on two main components: a silicon microstrip tracker and a YAG:Ce crystal calorimeter. Each proton trajectory is sampled by the tracker in four points: two upstream and two downstream the object under test; the particle residual energy is measured by the calorimeter. The apparatus is described in details together with a discussion on the characterization of the hardware under proton beams with energies up to 175 MeV.