Lawrence Berkeley National Laboratory

Neutron cross-section data are fundamental for the design of nuclear interrogation systems, the maintenance of nuclear materials and waste, and the understanding the consequences of nuclear catastrophe. Although a large body of nuclear data exists, it is often old, unreliable, or poorly determined. For several years we have collaborated, as part of an IAEA Coordinated Research Project, to precisely measure the partial thermal neutron gamma ray cross sections for all elements from hydrogen to uranium at the Budapest Reactor. These data will replace the unreliable tables of Lone et al [1], still widely in use, and will be published as an IAEA TECDOC.