The main objective of this work is to develop user-friendly software, called BXCOM, for computation of the exposure build-up factor (EBF) and the energy absorption build-up factor (EABF), using geometric progression (G-P) fitting method for element, compound or mixture in the energy region 0.015–15 MeV, and for penetration depths up to 40 mean free path (mfp). Furthermore, BXCOM can generate the equivalent atomic number $\left(Z_{\text{eq}}\right)$ and five fitting parameters used in the G-P method for mixtures and compounds over an interval of photon energies extended from 0.015 to 15 MeV. In addition, the program is designed to calculate the effective atomic number $\left(Z_{\text{eff}}\right)$ and effective electron number $\left(N_{\text{eff}}\right)$ via the direct method. BXCOM program has been verified by comparing its results with approved data by American National Standards Institute. BXCOM runs under MS Windows® operating system. It has an improved user interface that provides examination of material's radiation interaction parameters. Finally, BXCOM allows rapid and reliable calculation of many γ-ray interaction parameters such as $\left(Z_{\text{eq}}\right)$, $\left(Z_{\text{eff}}\right)$, $\left(N_{\text{eff}}\right)$, G-P fitting parameters and build-up factors that are essential in a wide range of applications such as radiation shielding, radiotherapy, technology and so on.

In the present study, commercially important high-performance polymers and their composites have been investigated with respect to photon interactions as means of mass attenuation coefficient (μ/ρ), mean free path (MFP), half-value layer (HVL), effective atomic number (Z_eff), effective electron density (N_eff), and energy absorption and exposure buildup factors (EABF and EBF) at different photon energies. For this purpose, sample plates were prepared by extrusion and injection techniques using polyethersulfone, polyetherimide, acrylonitrile butadiene styrene copolymer, polyamide 66, polyphthalamide, and polypropylene copolymers as high-performance polymers and glass and carbon fibers as reinforcement. The (μ/ρ)s of the materials were measured at 81 and 356 keV photon energies to determine MFP, HVL, Z_eff, and N_eff. The theoretical values of these parameters were calculated via ZXCOM, WinXCom and Monte Carlo N-Particle simulation code (MCNP), and a good agreement was obtained between WinXCom–MCNP and MCNP–Exp. Finally, EABFs and EBFs of the samples were calculated up to around 40 MFP in the energy region 0.015–15 MeV and significant variations were observed in the continuous energy and MFP regions.