Methods for VHEE/FLASH Radiotherapy Studies and High Dose Rate Dosimetry at the CLEAR User Facility

The CERN Linear Electron Accelerator for Research (CLEAR), operating since 2017, is a user facility providing electron beams for a varied and large range of experiments. The accelerator can generate a 60-220 MeV electron beam and it was recently selected to study the feasibility of using Very High Energy Electrons (VHEE) at Ultra High Dose Rate (UHDR) for cancer radiotherapy. One of the studies in CLEAR is to study the impact of sending the total dose in a short amount of time (also called UHDR) and study the FLASH biological effect in which deep-seated cancer cells are damaged while the healthy tissues are spared. The dosimetry in CLEAR is measured using both passive dosimetry with radiochromic films or radio-photo-luminescent dosimeters. In this paper different methods for dosimetry studies and experiments in which they are used will be presented.