Validation of a Proposed Equation for Determining the Half-Thickness Value of Gamma and X-Ray Radiation

Half-value layer (HVL) is energy dependent on the photon, much as the attenuation coefficient. Increasing the penetrating energy of a photon stream causes an increase in a substance's HVL. Before calculating the HVL value, the linear attenuation coefficient (μ) must be established. A review of the literature indicated that there is presently no Monte Carlo-based sufficient tool for direct calculation of the HVL value and direct computation suitable for material design and all changes based on sophisticated simulation methods. This study aims to calculate HVL data with GAMOS simulation in the 0.1-20 MeV energy range for some anatomical structures defined in ICRU-44 (bone cortical, brain, gray/white matter, breast tissue, eye lens, and testis). The HVL values of the anatomical structures used in the GAMOS code were compared with the results in the literature. As a result, HVL values obtained from GAMOS simulation for different materials and biological structures were compatible with the literature.