Portable, High Resolution, Combined Neutron/X-ray Imaging System

NNSA plays a vital role in the U.S. government’s efforts to prevent, respond to, and counter terrorists or other adversaries with a nuclear/radiological device. High-resolution neutron/X-ray radiography imagers are critical to accomplish this goal. X-ray sources needed for the task are readily available and fast neutron sources with high flux that meet the SWaP requirements have been developed. Unfortunately, detectors that are simultaneously sensitive to fast neutrons and high energy X-rays and can generate high-resolution images in short time duration, don’t exist. We are developing an advanced detector to address this need. The proposed research directly addresses the DOE/NNSA’s mission needs with the development of a portable, high spatial resolution, combined neutron/X-ray radiography detector. The envisioned detector would be capable of high sensitivity imaging of fast neutrons and high energy X-rays and could also be operated at high frame rates. The detector will employ a newly discovered, high performance, structured, solid-state sensor coupled to a large area readout to provide image data in digital format. The Phase II advanced the technology via (1) sensor design and simulations, (2) fabrication of sensors and characterization studies, (3) assembling prototype detector and performing evaluations using fast neutrons and high energy X-rays, and (4) demonstrating high-resolution imaging using MeV neutrons and X-rays. We worked closely with the ORNL researchers and DOE program officials through periodic reviews for planning translation of this transformative technology into their application space. The goal of the Phase IIA is to develop a fully functional detector and conduct testing under realistic field conditions with the help from our ORNL collaborators. We will develop protocols to manufacture large-area sensors with the desired sensitivities, structures, and imaging properties. This iterative process will involve simulations, fabrication, and characterization to yield the sensor with desired dimensions. The large-area sensor will be integrated into the selected readout and after preliminary tests at RMD, the detector will be tested at ORNL using DD/DT generators and 7.5 MeV X-ray source. A large-area detector capable of high sensitivity, high spatial resolution for neutrons and Xrays is needed for numerous applications in homeland security, nondestructive testing, and military hardware testing, to name a few. From a scientific perspective, such a detector will be well-suited for determining atomic positions and displacement parameters of light elements (such as hydrogen) next to heavy metals in advanced materials or new drugs, and will be an ideal solution for studying magnetic structures, phase transitions, disorder, and local structure phenomena. Research in each of these areas will directly benefit the public by accelerating the development of new drugs, novel materials, and systems, all of which have a direct impact on health care, quality of life, addressing the nation’s future energy needs, and it will expand our technology base.