Microstructured plastic scintillators for pencil beam profiling in proton-therapy accelerators

A novel beam profiler based on microstructured scintillation resin is presented. The detector consists of a bundle of waveguides, featuring an active area of 30 × 30 mm2 with a fill factor of 50% and a pitch of 400 μ m. This configuration is obtained by casting a scintillating resin into a microfabricated Polydimethylsiloxane (PDMS) mold. A prototype, coupled to an array of photodiodes and readout electronics, potentially allowing profile rates up to 7 kHz, has undergone testing with an ultraviolet (UV) source and a proton beam accelerated at different energies, typical of those employed in proton therapy. The experimental results obtained during the test campaigns were compared with theoretical simulations demonstrating a good agreement with the modeling expectations, thus confirming the validity of this novel design for microstructured scintillating detectors.