Photonic Crystal Based Radiochromic Film for Visualizing the Spatial Dose Distribution of Electron Beams

Electron‐beam (e‐beam) technology plays a crucial role in high‐dose (MGy) irradiation applications, which heavily rely on high irradiation efficiency and uniform dose distribution. However, the immediate visualization of precise e‐beam dose and spatial dose distribution is challenging due to high‐throughput flux and strong electron scattering. Herein, a wide dose‐response range (0–3.75 MGy) and high spatial resolution (<100 μm) e‐beam dosimetry based on photonic crystal (PC) polymer films is developed. The diffraction peak of the PC film demonstrates a continuous blue shift within the visible light wavelength range as the dose increases. This phenomenon is attributed to the gradual collapse of the inverse opal structure under irradiation. The naked‐eye readable dosimeter shows excellent pre‐and post‐irradiation stability, demonstrating remarkable resistance to environmental factors such as temperature fluctuations and ultraviolet exposure. Notably, the dosimeter can detect e‐beam scattering clearly when using a metal mask for radiation shielding. This work provided valuable insights into the radiation degradation behavior of PC structures under high‐dose e‐beam irradiation, while simultaneously offering a novel perspective for MGy‐level e‐beam dose and spatial distribution detection.