Woodruff School of Mechanical Engineering

NRE 8011/8012 and MP 6011/6012 Seminar

Nuclear & Radiological Engineering and Medical Physics Programs


Retrospective Imaging and Characterization of Nuclear Materials


Dr. Robert Hayes


North Carolina State University


Thursday, March 9, 2017 at 11:00:00 AM


Boggs Building, Room 3-47


Dr. Erickson


Modern techniques for detection of covert nuclear material requires some combination of real time measurement and or sampling of the material. More common is real time measurement of the ionizing emission caused by radioactive decay or through the materials measured response to external interrogation radiation. You can expose the suspect material with various radiation types including high energy photons such as x-rays or with larger particles such as neutrons and muons to obtain images or measure nuclear reactions induced in the material. Stand-off detection using imaging modalities similar to those in the medical field can be accomplished or simple collimated detectors can be used to localize radioactive materials. In all such cases, the common feature is that some or all of the nuclear materials have to be present for the measurement which makes sense as one might ask, “how you can measure something that is not there?” The current work and results show how to do exactly that, how to characterize nuclear materials after they have been removed from an area leaving no chemical trace. This new approach is demonstrated to be fully capable of providing both previous source spatial distribution and emission energy grouping.


Dr. Hayes is an Associate Professor of Nuclear Engineering at North Carolina State University in Raleigh. He is also a Certified Health Physicist, a licensed Professional Engineer in Nuclear Engineering and a Fellow of the American Physical Society. His previous experience includes time at the Nevada Test Site doing radiological emergency response and at the Waste Isolation Pilot Plant where he conducted the consequence assessment for their radiological event.