Fast silicon detectors as proton therapy beam monitors

Objective.The study investigates the response of low gain avalanche detectors (LGADs), which are fast silicon sensors, for potential use in high-resolution proton beam monitoring.Approach.Data is analysed from LGADs placed in the 60 MeV proton beam of the AIC-144 cyclotron.Main results.Several features of the pulse structure of the cyclotron are observed for the first time. The detector and acquisition system tested provide accurate flux measurements up to an instantaneous dose rate of about 7.5 Gy s^-1. Above this, there is an efficiency loss due to multiple protons crossing the detector, which could be addressed through a redesign of the sensors and electronics.Significance.The findings suggest that LGADs offer a viable alternative for proton therapy beam diagnostics.