Liquids Reflectometer (BL-4B) and Some Science Examples | NNSS 2025 at ORNL

Liquids Reflectometer (BL-4B) and Some Science Examples Presented by Hanyu Wang 1st National Neutron Scattering School, 2025 Oak Ridge National Laboratory (ORNL) In this lecture, Hanyu Wang introduces the Liquids Reflectometer (BL-4B) at the Spallation Neutron Source and demonstrates how neutron reflectivity is applied to soft matter and interfacial systems. The presentation explains how reflectometry provides depth-resolved structural information at liquid–air and liquid–solid interfaces, enabling detailed studies of thin films, polymers, surfactants, and biological materials. Wang describes the design and capabilities of BL-4B, including its time-of-flight configuration, flexible sample environments, and suitability for studies of dynamic and complex liquid systems. The lecture outlines how reflectivity measurements are performed, how scattering length density profiles are extracted, and how contrast variation enhances sensitivity to specific components within multilayered or interfacial structures. Through selected science examples, the session illustrates how neutron reflectivity reveals nanoscale organization, adsorption behavior, and interfacial structure in soft matter systems. The presentation emphasizes how the Liquids Reflectometer enables quantitative structural characterization of buried interfaces and liquid systems that are difficult to access using other techniques. Learn more about neutron science at ORNL: https://neutrons.ornl.gov Learn about the National Neutron Scattering School at ORNL: https://neutrons.ornl.gov/nns