Paprica: The pair production imaging chamber

In the treatment of tumours with charged particle beams, several factors introduce uncertainties in predicting the beam range in the biological tissue. In the treatment planning, safety margins of several millimetres are added to the volume to be treated in order to avoid under-dosage of the tumour. Beam range monitoring techniques have been proposed and studied in order to reduce safety margins and ensure safer treatments. Some of these techniques detect secondary radiation emitted during beam-tissue interaction. The aim of the PAir PRoduction Imaging ChAmber project is to demonstrate the feasibility of a range monitoring technique based on secondary prompt-gamma radiation, detected by means of the pair production mechanism. The project results presented at the SIF Congress 2020 were deepened and updated with new Monte Carlo simulations.