TOFpRad: a novel proton radiography prototype based on Time Of Flight measurements

Abstract Ion beam therapy effectively treats radiation-resistant and deeply located tumors but requires meticulous planning and wide safety margins imposed by current technology. Proton transmission imaging, using protons instead of x-rays for image acquisition, is pivotal for precise treatment planning by directly probing the proton stopping power, reducing uncertainties, and enabling a fast verification of the treatment. In the last 15 years, proton imaging prototypes have primarily used calorimeter detectors. An alternative method measures proton Time Of Flight (TOF) to determine velocity and, subsequently, residual kinetic energy. The TOFpRad project aims to create a proton radiography prototype integrating a Time Of Flight (TOF) system and plastic scintillating fibers to monitor the position, direction, and residual energy of protons. A preliminary experimental apparatus was developed and tested at the National Center for Oncological Hadrontherapy (CNAO, Pavia). This article will outline the project and its objectives. Additionally, the results of this first data taking will be examined, allowing for an assessment of the performance of the detectors. These findings provide a foundation for future investigations aimed at developing a more advanced and efficient prototype.