Neutron and gamma shielding capabilities of Li and Na borate glasses

Abstract

Abstract Glass is an increasingly popular candidate material for radiation shielding in a variety of settings, including spacecraft design and medical safety. This study investigates the gamma and neutron shielding properties of various glass samples produced at Coe College, including several sodium and lithium doped borate and silicate glasses. The results are obtained through a series of test beam trials at a nuclear reactor, which were further supported by simulation in GATE, a Geant4-based tool. Evaluation tests included simulation of photon energies from 0.01 MeV to 20 MeV and neutron energies from 2 to 12 MeV. All candidate materials were poor shields for gamma radiation, hovering around 10% prevention, the glass samples with the highest packing fractions yielding the best results. According to the mass attenuation coefficients (MAC), half value layer (HVL), and tenth value layer (TVL) calculated in this study, 0.6Na2O*SiO2 and 0.2Li2O*B2O3 provide the best shielding between 0.01–20 MeV of gamma radiation among the glasses tested in this study. Neutron shielding tests were more promising, with the borate glasses yielding the best results. Among all glasses, 0.4Li2O*B2O3 provided the best results blocking about 85% of the incident neutron radiation and 0.6Na2O*SiO2 yielded the worst shielding, blocking less than 20 % of the neutrons. Simulations show that the three xLi2O*B2O3 glasses have the highest fast neutron removal cross section (Σ R ), indicating their higher level of protection against fast neutrons, consistent with the test beam results.