Capability of lunar regolith with hydrogenous materials as shielding material against GCR and SPE on the surface of Moon studied using OLTARIS

Apart from Earth, the Moon is the most frequently observed celestial body and the most probable place of habitation beyond our mother planet. One of the significant challenges for habitation is the radiation resulting from the combination of Galactic Cosmic Rays (GCR) and Solar Particle Events (SPEs) experienced on the Moon’s surface. Unlike on Earth, there is no protection for a potential habitation zone on the Moon because of its weak magnetic field and extremely thin atmosphere. Incorporating lunar regolith into habitation shielding on the Moon is a promising approach for providing sufficient shielding while reducing the work involved in bringing building materials to the Moon. The interior wall of the regolith-built habitat could be covered in materials rich in hydrogen, which offer complementary radiation protection when being used together with lunar regolith while simultaneously protecting the interior of the housing from the slightly unsafe lunar regolith. In this publication, we compare several hydrogen-rich materials (polystyrene, polypropylene, Kevlar, Mylar, and Lithium hydride) for this application using OLTARIS simulations of effective dose equivalents inside a simulated habitation model. We find that among the hydrogen-rich materials used together with lunar regolith, lithium hydride for GCR and polypropylene for SPE yield the best shielding properties. Additionally, we investigate the thickness of the lunar regolith necessary to provide shielding against GCR. We also examine the differences in GCR shielding depending on the characteristics of the regolith in different regions of the Moon.