A study on the production method of thin films for low-energy beta measurement

The primary standard for coincidence counting of 4πβ(PPC)-γ requires thin films that minimize the attenuation of beta particles. In this study, we developed a method to control the thickness of these films. Traditional methods for producing thin films often resulted in wrinkles over time; however, our newly developed approaches allow for the production of wrinkle-free thin films with adjustable thickness. We designed specialized equipment for thin film production and analyzed the relationship between solution volume and resulting film thickness. Films were produced using a mixture of collodion and isopentyl acetate with volumes ranging from 20 μL to 80 μL, resulting in thicknesses from approximately 40 nm-160 nm. The effect of film thickness on low-energy radiation was experimentally analyzed using ⁵⁹Ni sources and compared with Monte Carlo simulations. Results confirm that film thickness significantly affects the measurement of low-energy electrons like Auger electrons, while having minimal impact on X-rays of similar energy.