Improving the nuclear data base for non-proliferation and homeland security

Many of the technical advances in non-proliferation and homeland security require calculations of transport of neutrons and gamma-rays through materials. The nuclear data base on which these calculations are made must be of high quality in order for the calculated responses to be credible. At the Los Alamos Neutron Science Center, three spallation neutron sources are being used to provide high-quality cross section and structure data with reactions induced by neutrons. Neutron transmission, neutron-induced fission and capture cross sections, neutron emission in fission, and gamma-ray production by neutrons are principal areas of research. Furthermore, these sources are also being used to validate calculations of the characterization and response of new detectors and detection techniques. Current research activities are summarized here