Assessment of Pleurotus ostreatus and Pleurotus citrinopileatus mushroom as bioshielding materials for neutron attenuation in medical cyclotron

Neutron absorbance efficiency is crucial for radiation shielding and nuclear reactors, with mushrooms like Pleurotus Ostreatus (PO) and Pleurotus Citrinopleatus (PC) enhancing this property due to their nitrogen, phosphorus, potassium, cadmium, and carbon content. Processed into 3 × 3 inch blocks at the National Institute of Nuclear Medicine and Allied Science (NINMAS), the mushrooms are dried at 80°C and ground to powder for analysis. Structural studies using XRD, FESEM, FTIR, and UV-vis spectroscopic reveal high carbon and oxygen levels. For the PO, the XRD investigation showed a broad diffraction peak that corresponded to an estimated crystallite size of about 1.34 nm, while PC showed a mostly amorphous structure devoid of clear crystalline diffraction peaks. The FTIR identifies various functional groups, and UV-vis spectra confirm the presence of sulfur and carbon. Neutron interaction mechanisms in mushroom-derived shielding materials involve moderation and scattering by the hydrogen-rich matrix, followed by capture at nitrogen and sulfur sites. HPGe spectroscopic confirms effective neutron interaction and attenuation via the detection of activation products such as K-40 in this study. Both samples show significant K-40 levels of 30 Bq/kg, while Th-232 and U-238 are found to be 2–3 Bq/kg and 5–6 Bq/kg, respectively. The findings demonstrate that these mushroom blocks are not neutron-transparent, but rather contribute to neutron moderation and absorption acts as a bio-shielding materials in the cyclotron facility.