We propose to use the gamma-gamma coincidence technique to increase the sensitivity of gamma spectrometry and to spatially localize fission product samples within large volumes

This federal Cooperative Agreement award, funded by the Department of Homeland Security's Countering Weapons of Mass Destruction office, supports research under the National Nuclear Forensics Expertise Development Program (CFDA 97.130). The $297,283 award to Texas A&M University, effective Sep 30, 2024 through Sep 29, 2027, will be used to develop new analytical methods and optimize detector setups for the gamma-gamma coincidence technique to increase the sensitivity of gamma spectrometry and spatially localize fission product samples. The research will utilize unique neutron-irradiated uranium dioxide samples and leverage experts in nuclear spectroscopy, radiochemistry, and radiation detection. Two graduate students will be trained in data analysis and radiochemical methods as part of this project.

The coincidence method is widely used in fundamental nuclear structure physics and is known to significantly enhance signal-to-noise ratios. The spatial distribution of emitted gamma rays should also allow a source to be located within a large sample, so we will construct large samples ( 30-60 CM on a side) with embedded activity to test this approach. Our team has access to a set of unique neutron-irradiated uranium dioxide samples that can be used as fission product sources for these studies. We will acquire a small number of single-crystal germanium detectors, and these will be augmented by high-efficiency clover germanium detectors on loan from the clovershare collaboration. This research will be heavily synergized by utilizing experts in nuclear spectroscopy, radiochemistry, and radiation detection. Our collaborators from pacific northwest national laboratory also have existing expertise in gamma-gamma coincidence measurements. The two major outcomes of this project will be the development of new analytical methods and optimized detector setups and the training of two graduate students in data analysis and radiochemical methods.