The main goal of this award is to make NRF cross-section measurements on actinides and other materials of interest to the Domestic Nuclear Detection Office (DNDO). This work will be carried out using the High Intensity Gamma-ray Source (HIGS) at the Triangle Universities Nuclear Laboratory (TUNL). Among the data needed for developing and operating gamma-ray beam inspection systems are nuclear resonance fluorescence (NRF) data for isotope identification and photoneutron reaction data for identifying fissile materials. In addition, these data are important for applications in nuclear forensic techniques applied to analyzing pre-detonation and post-detonation materials. The research will be carried out by a collaboration of research groups from two institutions: Duke University and North Carolina A&T State University (NC A&T). Other collaborators include physicists from Lawrence Livermore National Laboratory, Los Alamos National Laboratory and Pacific Northwestern National Laboratory.
This research will contribute to the mission of the DNDO in four categories: (1) science relevant to developing technologies for non-intrusive inspection of cargo to reduce risk of radiological threats, (2) science important for developing capabilities for performing nuclear forensic on pre-detonation and post-detonation materials, (3) science and engineering of novel radiation detector technologies, and (4) the scientific workforce needed to develop new technologies important to the mission of DNDO and to carry out the duties of the Department of Homeland Security. The project will provide research opportunities for graduate and undergraduate students at several universities including Duke University, NC A&T State University, NC State University and Florida A&M University. The research will be conducted in the educationally rich environment at TUNL which currently has about 45 PhD degree graduate students. Because research groups at TUNL are typically small, the students have the benefit of routinely working closely with faculty and postdocs in an apprenticeship style. The involvement of the research group from NC A&T and with students at Florida A&M have the added benefit of giving students at these Historically Black Universities experience with using leading edge particle and gamma-ray detection technologies and developing experimental techniques that are relevant to addressing high-priority national security issues.
The development of gamma-ray beam based systems for interrogation of cargo is guided by sophisticated computer simulations that model the interaction of gamma-rays in the container walls and the contents of the cargo. This project provided cross-section data for nuclear resonance fluorescence (NRF) on special nuclear materials that are important for developing accurate models. The isotopes studied in this project were 239Pu, 240Pu and 233U. The measurements were performed using linearly polarized gamma-ray beams from the High Intensity Gamma-ray Source (HIGS) at the Triangle Universities Nuclear Laboratory. This research was conducted by a collaboration of groups from Duke University and North Carolina A&T State University. In addition to nuclear data measurements, the collaboration worked on developing nano-crystal scintillating materials for gamma-ray and neutron detection. This detector R&D work was interdiscliplinary, involving research groups in chemistry and physics at Duke University. Students and postdocs gained experience in nuclear structure research and high-resoluton gamma-ray spectroscopy and had opportunities to work in a variety of state-of-the-art research laboratories at Duke University, e.g., the HIGS facility and laboratories in the chemistry department that are equipped for material synthesis and photo-physical characterization of nanostructure materials. The students were involved in all aspects of projects: concept development, experiment design, technique and instrumentation development, experiment setup, data accumulation, data analysis, and results interpretation and dissemination. Opportunities for acquiring expertise in techniques at the frontiers of nuclear physics and particle detection technologies were broaden by allowing students to work on multiple projects within the collaboration. The detector development work provided students with opportunities to work in an interdisciplinary environment of physical chemists and nuclear physicists. The experimental techniques and technologies used by the students included high-density and high-speed signal processing electronics, particle detectors, nano-material synthesis and characterization, scintillation detection, data analysis, and computer modelling and simulation of physical processes.
