Comparative Monte Carlo study of transparent protective layers for beta radiation attenuation in betavoltaic applications

Abstract

This study investigates the beta radiation shielding and transmission performance of transparent polymers and glasses used as protective layers in commercial p-i-n diodes for betavoltaic systems. To the best of our knowledge, this study presents the first comprehensive application of the Half Absorption Thickness (HAT) metric to transparent polymers and glasses, providing a novel quantitative parameter for optimizing beta shielding performance. MCNP6.2 simulations were performed for seven beta sources (H-3, Ni-63, C-14, Pm-147, Sr-90, Y-90, Tc-99) and five materials (PMMA, SMMA, PC, Pyrex, glass) over nanometer-millimeter thicknesses. Transmission strongly depended on material type and source energy; glass attenuated 94 % of H-3 at sub-micron thickness, while PC transmitted over 30 %. The Half Absorption Thickness (HAT) metric revealed nanoscale attenuation differences, such as 600 nm in PC. Logarithmic regression models (R-2 > 0.99) allow rapid performance estimation, providing a quantitative basis for material selection in betavoltaic batteries, medical diagnostics, aerospace sensors, and radiation-hardened electronics.