Determination of topographical radiation dose distribution of high-dose low-energy proton beam via processing digital image of photonic crystal films

The precise determination of 2D dose distribution at high doses and convenient dose measurement methods are ongoing challenges in the study of beam diagnosis on large-scale scientific devices. The current work offers an impressive solution by integrating PEGDA photonic crystal films with HSB (Hue, Saturation, Brightness) image processing technology. Under irradiation by a proton beam with a low energy of 182.5 keV, the dose dependence of the radiochromic properties of PEGDA films was confirmed in the experiment. Low-energy protons can alter the microstructure of PEGDA films during energy deposition, reducing the characteristic distance and decreasing the diffraction center wavelength. Under irradiation by proton beams with high doses from 1 MGy to 17.6 MGy (on average), the PEGDA films exhibited a significant blue shift in color phase, with a clear linear relationship between wavelength and absorbed dose. This study offers a straightforward and effective real-time dose feedback analysis method compared to traditional radiochromic readout systems. This approach, which is based on visual observation and digital image analysis, could provide a precise assessment of dose distribution through intuitive image interpretation. In summary, this work introduces a direct and effective dosimeter along with a simple and rapid method for dose readout, offering valuable validation for beam diagnosis.