Attenuation coefficients and exposure buildup factor of some rocks for gamma ray shielding applications

• Published in: Radiation physics and chemistry (Oxford, England : 1993) Vol. 148; pp. 86 - 94
• Main Authors: Obaid, Shamsan S., Sayyed, M.I., Gaikwad, D.K., Pawar, Pravina.P.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2018; Elsevier BV
• Subjects: Atomic properties; Attenuation coefficients; Basalt; Chemical bonds; Chemical reactions; Cross-sections; Electron density; Energy absorption; Gamma rays; Granite; Limestone; Marble; Mass attenuation coefficient; MCNP5; Olivine; Physics; Radiation; Radiation shielding; Radioisotopes; Rock; Rocks; Shielding; Sodium 22; MCNP5; Rock; Shielding; Mass attenuation coefficient
• ISSN: 0969-806X; 1879-0895
• DOI: 10.1016/j.radphyschem.2018.02.026

In the present work, the mass attenuation coefficient µ/ρ is investigated experimentally and theoretically for seven rocks (olivine basalt, green marble, jet black granite, telphone black granite, cuddapah limestone, white marble and pink marble). The rock samples were collected from different places of India. The mass attenuation coefficients of the samples were measured experimentally at photon energies of radioisotopes Co57 (122 keV), Ba133 (356 keV), 22Na (511 and 1275 keV), Cs137 (662 keV), Mn54 (840 keV), and Co60 (1330 keV). Theoretically, the simulation results of µ/ρ using both XCOM and MCNP5 codes were compared with experimental results and a satisfactory agreement was observed. Total atomic cross sections (σt,a) electronic cross sections (σt,e), effective atomic number (Zeff), electron density (Ne) and half value layer (HVL) were evaluated using the obtained µ/ρ values for investigated rocks. The HVL values for the selected rocks were compared with some common shielding concretes. Moreover, by Geometric Progression method (G-P) exposure buildup factor (EBF) and energy absorption buildup factor (EABF) values were calculated for incident photon energy 0.015–15 MeV up to penetration depths of 40 mean free paths. The results show that among the studied rocks pink marble possesses superior shielding properties for γ-ray. This work was carried out to explore the advantage of utilizing the selected rocks in engineering structures and building construction to shield gamma-rays. •Measurement of gamma ray shielding properties of some rocks.•Experimental results are compared with Xcom and MCNP.•Exposure buildup factor has been determined to understand the shielding capability of rocks.•Rocks are good candidates for shielding against ionizing radiation than concretes.•Pink marble is efficient gamma ray shielding material.