The National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR) is a national user facility whose mission is to ensure the availability of neutron measurement capabilities in order to meet the needs of U.S. researchers from industry, academia, and government agencies. This mission is aligned with the mission of NIST, which is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve the quality of life. As requested by the Deputy Director of NIST, this book assesses NCNR, based on the following criteria: (1) the technical merit of the current laboratory programs relative to current state-of-the-art programs worldwide; (2) the adequacy of the laboratory budget, facilities, equipment, and human resources, as they affect the quality of the laboratory technical programs; and (3) the degree to which the laboratory programs in measurement science and standards achieve their stated objectives and desired impact.