Impact of micro/nano cadmium oxide on shielding properties of cement–ball clay matrix

This study investigates the gamma radiation shielding properties of cement–ball clay matrix composites doped with micro- and nano-sized cadmium oxide (CdO) particles. The linear attenuation coefficient (LAC) was determined using a sodium iodide (NaI) detector and five radioactive point sources with energies ranging from 59.5 to 1408 keV. The LAC values obtained were compared to the XCOM database and found to be in good agreement. The composites' half-value layer (HVL), tenth value layer (TVL), mean free path (MFP), effective atomic number (Z(eff)), equivalent atomic number (Z(eq)), and absorption buildup factor (EABF) were determined. The results showed that the addition of CdO particles improved the radiation-shielding behavior of the composites and increasing the weight fraction of CdO particles increased the shielding effectiveness. The results also illustrated that when nano-sized CdO particles were compared to their micro-sized counterparts, there was a significant enhancement in radiation shielding effectiveness. For instance, a composite material composed of 50% cement, 41.7% ball clay, and 3.8% nano CdO at an energy level of 0.0595 MeV exhibited a remarkable 12.2% increase in attenuation, surpassing the performance of the micro-sized sample with an equivalent concentration. Similarly, another composite consisting of 50% cement, 33.3% ball clay, and 16.7% nano CdO demonstrated a significant 15.4% increase in attenuation at the same energy level, when compared to the micro-sized sample. The study demonstrates the potential of CdO-doped cement–ball clay matrix composites for gamma radiation shielding applications.