On the registration of low energy alpha particle with modified GafChromic EBT2 radiochromic film

The objectives of the current work are to investigate the modification of the self-developed GafChromic EBT2 radiochromic film, to register 2 MeV alpha particles, by eliminating the polystyrene layer of 50 mu m and the adhesive layer of 15 mu m. Such modification enables 2 MeV alpha particles to reach and interact directly by the diacetylene monomers active layer of thickness 30 mu m. The modified EBT2 radiochromic film, EBT2-M was irradiated by alpha-particles of 2 MeV starting from 1 h to 300 h in a clean dark room; one day later the irradiated EBT2 films were scanned with a flatbed scanner, and the absorbance spectra were measured by UV-VIS spectrophotometer. The obtained results reveal that the darkness of the irradiated EBT2-M film increases with the increasing of the exposure time to 2 MeV alpha particles, but for a prolonged exposure time the darkness is saturated. The UV-VIS absorbance spectra at 502 nm, 525 nm, 582 nm, 602 nm, and 631 nm are correlated with exposure time to 2 MeV alpha particles, which is, in turn, the absorbed dose by an exponential growth function that saturates at a prolonged exposure time, when diacetylene monomers are completely polymerized. The color channel level Red, Green, and Blue resulting from split RGB image was determined and investigated as a function in the exposure time to the alpha particle of 2 MeV, the color scale level decreases exponentially with the increase in exposure time. The reported results of the grey, red and green color scale have similar absorbance whereas the blue color channel shows insignificant behavior. The presented results pave the way to use the modified EBT2-M radiochromic film to mapping the relative dose delivered by low-energy alpha particles.