The impact of pressure rate on the physical, structural and gamma-ray shielding capabilities of novel light-weight clay bricks

The present study focuses on investigating the gamma-ray protection features of clay bricks for potential use in radiation shielding fields. The study examined the physical and structural features that affect the performance of these stones in shielding γ-rays. The density (ρ, g/cm³) of the clay bricks samples was measured utilizing the MH-300A density meter. Additionally, the mineral structure within the annealed pressed clay samples was identification the XRD spectrometry. Moreover, the morphology and elemental chemical composition for the annealed bricks were examined using a Thermo Scientific Prisma E, USA field emission Scanning Electron Microscope (SEM) in conjunction with Energy Dispersive X-ray Spectroscopy. Besides, the shielding features of the clay bricks were analyzed using the experimentally measurements (by NaI (Tl) scintillation detector), XCOM software, and Monte Carlo Simulation over the γ-ray energy interval of 0.033–1.332 MeV. The findings of the study indicate that an increase in the pressure rate within the clay bricks samples leads to the rise in their density (from 1.62 to 1.87 g/cm³). This increase in density is accompanied by a decline in both porosity (Φ, %) (from 34.75 to 26.21 %) and water absorption (K, %) (from 26.21 to 14.74 %) factors. Furthermore, the increase in pressure rate from 7.61 to 114.22 MPa also results in an increase in the linear attenuation coefficient (μ, cm⁻¹) of the clay bricks under study. This is achieved by increasing the μ values from 0.39 to 0.43 cm⁻¹, from 0.13 to 0.15 cm⁻¹, and from 0.09 to 0.10 cm⁻¹, at 0.081, 0.511 and 1.173 MeV, respectively. The synthetic bricks offer a lead-free and efficient option for protection, making them ideal for use in nuclear facility start-ups or in areas with radiation exposure.