Spectral characterization and comparison of EBT3, EBT4, and EBT-XD radiochromic films.

This study analyzed the spectral response of EBT3, EBT4, and EBT-XD radiochromic films using absorption spectroscopy. The primary focus was on characterizing the evolution of spectral signatures across a range of absorbed doses, thereby elucidating the unique dose-dependent response profiles of each film type. Ten samples of each film type were subjected to open field irradiation within their designated dose ranges (1-20 Gy for EBT3 and EBT4, 1-50 Gy for EBT-XD). The corresponding absorption spectra were recorded and studied via decomposition and parameterization of dose-dependent spectral features. Lorentzian profiles were employed for spectral decomposition. Each film type displayed unique spectral signatures with distinct absorption peaks: nine for EBT3, eleven for EBT4, and twelve constituent profiles for EBT-XD. Notably, the EBT4 film demonstrated a slight difference in the blue part of the absorption spectrum and a change in the response, relative to its EBT3 predecessor. Orientation dependence of the film spectra was most pronounced for the EBT3 film type, followed by a declining trend across EBT4 and EBT-XD films. Absorption spectroscopy portrayed distinct spectral fingerprints of the studied film types, aiding the selection of the most suitable film for specific applications.