Standoff detection of thermal and fast neutrons

Improved detection of weapons of mass destruction is one of the Science and Technology priorities of the Secretary of Defense for Fiscal Years 2013-2017. Unfortunately, the remote detection of special nuclear materials is difficult because the materials are not very radioactive, the radiation signatures decrease rapidly with distance, and faint sources of radiation can be obscured by naturally occurring and man-made radioactive sources. The Radiation Detection Section of the High Energy Space Environment Branch of the U.S. Naval Research Laboratory has developed a containerized fast and thermal neutron standoff detection system. The instrument was characterized with neutron sources at different standoff distances and at different drive-by speeds to determine the on-water performance of the system. Results of this measurement campaign will be discussed.