in: Computational Methods in Nuclear Radiation Shielding and Dosimetry, Kulwinder Singh Mann,Ph.D.,V. P. Singh, Editor, NOVA Science Publishers Inc. , New York, pp.277-292, 2020
In this chapter, the protection capacity of four different rock types (traditional, black, yellow, and grey ignimbrites) commonly used in the building industry against gamma radiation has been discussed using the FLUKA simulation method. Experimental analyses for determining the mass attenuation coefficients (μρ) of the rocks were performed by employing 60Co and 133Ba radioactive sources for 0.356, 0.662, 1.172, and 1.330 MeV photon energies. To verify the results, the μm values at the same energies were simulated with FLUKA codes and theoretically generated with XCOM. Then, for a wider energy range, 0.015-15 MeV, the μρ values were obtained and various parameters, linear attenuation coefficient (μρ), mean free path (MFP), energy absorption and exposure buildup factors (EABF and EBF) and HVL, that are important in gamma shield design have been found for all of the samples. From the results obtained, it has been observed that the chemical composition and density of the rocks affect their radiation protection abilities. It has been revealed that black and ordinary ignimbrites with high CaO and Fe2O3 contents got the smallest HVL, MFP, EBF, and EABF values while having the largest μρ and Zeq values. Among the selected samples, the black ignimbrite is the sample with the best gamma shielding features.