Applied Nuclear Physics - Nuclear Engineering Department

Benchmark Measurements of Delayed Fission Product Gamma Rays

Principal investigators: E.B. Norman, Lawrence Berkeley National Laboratory, and S.G. Prussin

Following the demonstration that delayed fission product gamma rays may be a robust signature for detecting fissionable materials embedded in thick cargos, an effort has been mounted to incorporate fission products and their gamma rays spectra directly into a Monte Carlo code for studies of system designs and sensitivity estimates. To provide a benchmark for the quality of such calculations, we are designing a well-characterized experimental scheme and will use it to measure the delayed gamma ray spectra from thermal fission of 235U and 239Pu under carefully controlled irradiation and decay conditions.

Investigation of Delayed Fission Gamma Rays as a Robust Signature for Nuclear Materials in Sea-going Cargo Containers

Supported by the Department of Homeland Security

In conjunction with senior scientists from the Lawrence Livermore and Lawrence Berkeley National Laboratories, we are assisting in a range of experimental and calculational activites designed to define the effectiveness of delayed fission gamma rays as a signature of the presence of fissionable materials embedded in thick cargos. The experimental measurements are designed to understand the practical issues of interferences, the characteristics of collimated neutron sources as the interrogating probe, etc. The calculational activities include support of system design and construction, the transport of the delayed gamma rays through various media, etc.