Dosimetric response of radiophotoluminescent glass detectors in a scanning pencil proton beam

The dose and linear energy transfer (LET) dependence of the radiophotoluminescence (RPL) response was evaluated for RPL glass detectors, taken from the environmental dosimeter type SC-1, using a clinical 100 MeV and 200 MeV scanning pencil proton beam. The measurements were performed at different positions along the Bragg curves. The fluence-averaged (LETf) and dose-averaged (LETd) LET at the positions of the detectors were calculated using two Monte Carlo codes (MCNP and PHITS). Before measurements in proton beams, the linearity of the dose response for the dose range of interest (up to 10 Gy) was checked and confirmed in a Co-60 gamma ray field, since the FGD-202 reader for SC-1 dosimeters is usually used for doses up to 1 Gy and we found no data for higher doses in the literature. For proton beams, the linear dose response was determined for the doses investigated from 0.5 Gy to 8.8 Gy. For the LET range, which corresponds to the LETd from 0.47 keV/mu m to 4.70 keV/mu m, a decrease in response with an increase in LET was observed.