Applying the SANS technique to characterize the pore space of an argillaceous rock.

• Analysis of the pore network in Tamusu mudstone based on PDSM. • A predominant presence of nanoscale pores in mudstone. • The PSD curves exhibit multiple peak distributions. • More than half of the pores within Tamusu mudstone lack connectivity. This study focused on the Tamusu mudstone, a candidate rock for high-level radioactive waste (HLW) disposal in China. Utilizing small-angle neutron scattering (SANS) as our primary tool, we provide a comprehensive geometric analysis of the entire pore network, including both open and closed pores, within this target rock. Our results reveal the substantial presence of nanoscale pores in the Tamusu mudstone. The pore size distribution (PSD) curve exhibits a multimodal distribution, with more than half of the unconnected pores contributing to variations in the distribution of connected and total pores. [ABSTRACT FROM AUTHOR]