A solar flare simulation and dosimetry facility at a proton therapy cyclotron

During extravehicular activities (EVA) astronauts are exposed to intense radiation from solar flare events (SFE). Hence, the radiation shielding efficacy of space suits, in particular the helmets and extra vehicular visor assembly (EVVA) are imperative to safety of astronauts and ultimate success of the space mission. At West German Proton Therapy Centre Essen (WPE) we have replicated the historical solar flare spectra by manipulating the treatment planning system (TPS) of the 230 MeV proton-therapy cyclotron and developed novel proton irradiation and dosimetry methods for the testing of space borne devices as mentioned above. We have used a single foil of radiochromic film (type EBT 2) to estimate the proton depth dose distribution in the human eye. The optimal thickness of EVVA (acryl glass) for the protection from solar flares was estimated to be 2.35 cm. A maximum SFE proton dose up to 20 Gy found to be well assessed using the EBT 2 films.