Investigation of gamma radiation shielding properties of various ores

Mass attenuation coefficients (μ/ρ, cm2/g) for some pellet samples produced using barite, magnetite, limonite, hematite and serpentine ores at 81, 276, 302, 356, 383 keV photons emitted from 133Ba and 121, 244, 344, 444, 778 keV photons emitted from 152Eu have been determined by using HPGe detector. Effective atomic numbers (Zeff) and electron densities (Ne) of the ores calculated in the selected energies.. The agreement of measured values of μ/ρ, Zeff and Ne with theoretical calculations is quite satisfactory. Mass attenuation coefficients were found to be highest for barite. The Zeff and Ne values for barite are maximum, for serpentine are minimum. Gamma ray energy absorption (EABF) and exposure buildup factors (EBF) were computed for ore samples using the five-parameter Geometric Progression (G-P) fitting method in the energy range 0.015-15 MeV for penetration depths up to 40 mean free path. Variations of EABF and EBF with incident photon energy and penetration depth were also investigated. It has been observed that among the selected ore samples, barite has lowest values for EABF and EBF in the intermediate energy region. Buildup of photons is more for serpentine. Exposure buildup factors (EBF) of given ores were compared with lead, steel-magnetite concrete (SM), concrete and bismuth borosilicate glass (BBS) with %20 mol Bi2O3. Barite is superior in terms of shielding properties among the other ore samples. The present study may be useful for radiation shielding applications.