Real-time Plastic Scintillation Dosimetry of Ultra-High Dose Rate Very High Energy Electrons (VHEE) at CERN CLEAR Facility

Abstract

Abstract Very High Energy Electrons (VHEE) that can theoretically treat deep-seated tumours and be delivered at ultra-high dose rates (UHDR) could be the solution to translate FLASH radiotherapy into the clinic. Standard dosimeters have limited application in those extreme conditions, but dose-rate independent and fast-response plastic scintillation detectors (PSDs) are a potential alternative to overcome this. In this work, response of a 4-channel PSD to the 200 MeV VHEE UHDR beam delivered with doses and dose rates in pulse up to 90 Gy and 4.6 × 109 Gy/s, respectively, at the CLEAR facility in CERN was characterized, using the Hyperscint RP200 platform. Scintillation light linearity with dose was observed for three scintillators from ∼5-50 Gy, while clear eiber output was linear up to 90 Gy. While linearity on this dose range was conserved even after radiation damage by exposure to 37.2 kGy total accumulated dose, light output signieicantly decreased. This work proves the potential of plastic scintillators for real-time dosimetry of UHDR VHEE beams.