Digital Neutron Imaging Proves Buckeyes are One Tough Nut

When you want to know if you have a broken bone, an X-ray is the best way to get an image. When researchers want to know about the interior of large or dense objects, neutron radiography can be the answer. Neutron radiography is a nondestructive method for imaging the internal form of samples by measuring the neutrons that are not absorbed when passing through the sample. It provides contrast between certain sample materials in a complementary manner to other imaging techniques, such as X-ray radiography. Neutron radiography and tomography (3D imaging) have been used for a wide variety of applications, such as studying cultural heritage objects, fuel cells, nuclear fuels, and for quality control of industrial products. Specialty applications, such as imaging highly radioactive fuels or using fast neutrons to image large or dense objects, are emerging in the field of digital neutron imaging.

Bill Chuirazzi, a PhD Candidate in Nuclear Engineering at The Ohio State University, has worked to optimize neutron detection for imaging through a combinatorial study as part of his recent dissertation. Part of Chuirazzi’s work on optimizing fast neutron scintillators utilized The Ohio State University Nuclear Reactor Laboratory (NRL) beam facility for neutron imaging. Bill was then awarded a 2-year Idaho National Lab (INL) fellowship and has been working there since August 2018. As part of his research, he imaged buckeye nuts, the eponymous nut to The Ohio State University, to demonstrate the difference in X-ray and neutron imaging. These images of buckeye nuts give the State of Ohio and the university the evidence of something suspected long ago – buckeyes are one tough nut.

“X-rays and neutrons give us different information about samples because they interact with atoms differently. The difference in resolution between the images comes from the fundamental physics of the two imaging techniques. However, this fundamental difference is why examining an object with both techniques helps us develop a better understanding of what is inside”, said Chuirazzi, who successfully defended his PhD dissertation on March 20th in a virtual format, due to the impact of the coronavirus epidemic crisis.

Using the same principles that produced the neutron image of the buckeye nut, Chuirazzi performed neutron radiography and tomography on nuclear fuel while a Graduate Fellow at INL. During this work, a new method for digitally imaging highly radioactive nuclear fuel was developed. In addition, his dissertation work advances the state-of-the-art of digital neutron imaging by developing new neutron detectors that have the potential to drastically increase detection efficiency and image resolution, producing better quality images. “Bill is tackling challenging problems in neutron imaging by enhancing the detection efficiency, but he has also extended the application of digital neutron imaging technologies”, said Dr. Raymond Cao, the director of NRL and also the advisor for Chuirazzi.

As the only operating research reactor currently in the State of Ohio, the NRL is a unique teaching and research laboratory that delivers high quality service to its customers and excellent instruction and research opportunities to nuclear engineering students. In 2017, the United State Department of Energy (DOE) designated the NRL as a partner facility of the Nuclear Science User Facilities program, allowing awarded researchers, often in collaboration with other laboratories and industry, to perform DOE mission-supporting research at the NRL. Two neutron beam facilities, one thermal neutron beam and one 1-MeV fast neutron beam, are available at NRL to provide capabilities for conducting neutron imaging research and applications.