Theoretical Evaluation of Alpha Particle Energy Loss for Some Non-Metals Using Bethe–Bloch Modeling and SRIM–IAEA Simulations

Abstract

Accurate prediction of alpha (α) particle stopping power and penetration depth is essential for effective radiological protection, medical physics applications, and nuclear instrumentation design. However, the interaction of α-particles with non-metallic media depends strongly on material density, atomic structure, and correctional effects such as shell and density corrections, making precise theoretical and numerical evaluation necessary for reliable prediction. This study therefore investigates the energy loss behaviour of α-particles in selected non-metallic materials using a validated computational approach. In this work, the Bethe–Bloch theoretical formalism, including density and shell corrections, was employed to calculate the stopping power and projected range of α-particles in air, water, and hydrogen over an energy range of 0.5–10 MeV. A discretized numerical integration algorithm was used to compute the penetration depth from the stopping power values. The computed results were validated through comparison with standard SRIM and IAEA reference datasets to assess the accuracy and reliability of the model. The results show excellent agreement between the computed and reference values, with percentage deviations below 0.12% in air and below 0.05% in both water and hydrogen, confirming the accuracy of the numerical method. It was observed that the stopping power decreases with increasing incident α-particle energy due to reduced interaction probability at higher velocities. Furthermore, denser media such as water exhibit significantly higher stopping power and shorter penetration depth compared to lighter gases such as air and hydrogen. The results also indicate that increasing the correctional pathlength leads to a slight decrease in stopping power, particularly in water, demonstrating the sensitivity of energy loss calculations to medium density and correctional parameters. These findings confirm the strong influence of material density and atomic structure on α-particle transport and energy deposition in non-metallic media. The results provide reliable predictive parameters for alpha-particle dosimetry, radiation transport analysis, and shielding design. This study supports the application of corrected Bethe–Bloch-based computational models as dependable tools for radiation protection planning, detector calibration, and medical physics applications. The outcome also contributes to improved safety standards and policy development in radiation shielding and radiological protection involving non-metallic materials.