First-of-its-Kind X-ray Imaging Tool for Studying Nuclear Materials

A new instrument at Brookhaven Lab combines four imaging techniques into one experimental setup, enabling comprehensive studies of materials for next-generation nuclear reactors

September 11, 2026

As the global energy demand continues to grow — driven in part by the rise of artificial intelligence — researchers are exploring technologies that can provide affordable, reliable, and safe sources of electricity. Nuclear energy is one option with the potential to meet around-the-clock energy demand. But realizing the next generation of nuclear reactors requires an in-depth understanding of the materials used for nuclear fuel, reactor components, and storage technologies — as well as how the materials’ properties change when exposed to radiation, corrosion, high temperatures, and mechanical stress.

“Nuclear reactors are designed to operate for several decades, but we cannot wait that long to understand how materials will hold up in extreme nuclear environments,” said Mehmet Topsakal, a materials scientist in the Nuclear Science and Security Department at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory.

Researchers like Topsakal leverage high-energy X-rays to unveil different characteristics of nuclear materials, like their internal structure and how their elements are distributed after exposure to extreme environments. One class of X-ray techniques — called computed tomography (CT) — builds a 3D picture of a material’s internal structure without destroying it or cutting it open. But scientists often need to conduct several different CT experiments to build a comprehensive understanding of their sample, similar to how medical doctors may order an MRI scan, blood work, and genetic sequencing to thoroughly evaluate a patient’s health. For both researchers and medical practitioners, all those tests rarely happen at once — or in the same place.

That’s why a team of Brookhaven Lab researchers has developed and built a single experimental setup where four different CT techniques can be conducted on the same experimental sample, establishing a holistic approach to fully characterize nuclear materials across a wide range of size scales, from the arrangement of individual atoms to a material’s overall structure. With this all-in-one approach, researchers can now reveal a material's internal structure, chemical makeup, and physical shape all at once. This is especially useful for studying complex materials that contain both highly ordered and disordered regions.

The new experimental setup — located at the X-ray Powder Diffraction (XPD) beamline of the National Synchrotron Light Source II (NSLS-II) — was commissioned collaboratively by the DOE’s Office of Nuclear Energy’s Nuclear Science User Facilities (NSUF) program, Brookhaven Lab’s Nuclear Science and Security Department, and NSLS-II. NSLS-II is a DOE Office of Science user facility at Brookhaven Lab.

The technical achievement — as well as a demonstration of the new capability — were recently published in the Journal of Synchrotron Radiation.

“NSLS-II is one of a few facilities in the world for studying dense, high-atomic-number materials, like nuclear materials, using an all-in-one method,” said Sanjit Ghose, XPD’s lead beamline scientist and one of the paper’s corresponding authors. “And that is due to XPD’s state-of-art, comprehensive capabilities.”

The XPD beamline delivers high-energy or “hard” X-rays that can penetrate, and thus characterize, heavy materials, like the steels that make up nuclear reactors and the fuels within that often contain actinides — a class of radioactive, metallic elements including uranium.

High-energy X-rays are important for X-ray Absorption CT, a technique that reveals a sample’s physical structure, including how its density varies and whether there are any cracks or voids. But what really sets XPD apart is its ability to also focus these hard X-rays down to a beam that is only 15 microns wide — about one-quarter the width of a human hair. With this small beam size, researchers can construct maps of materials’ structures and chemical compositions with remarkably high spatial resolution.

Using X-ray Fluorescence CT, for example, researchers can uncover the chemical elements that make up the sample and where they are located. At XPD, researchers can also dive deeper, probing the atomic-scale structure, using X-ray Diffraction CT for organized, crystalline materials and Pair Distribution Function CT for disordered, amorphous materials.

“Exposure to radiation alters materials and changes their structure, introducing defects and redistributing elements throughout the material,” explained Simerjeet Gill, deputy chair of Brookhaven’s Nuclear Science and Security Department and co-author of the new paper. “By conducting these four techniques simultaneously, we can pinpoint exactly where those chemical changes occurred and connect them to how the material's strength and brittleness have changed. That structure-composition-property relationship is what we want to understand when studying nuclear materials."

To put this experimental setup to the test, the Brookhaven researchers created a sample containing “a little bit of everything,” according to Topsakal, who is lead author on the paper. The sample combined metal wires of varying sizes and compositions with several powder materials, ensuring there were features that could be detected more efficiently with each of the four techniques. Ultimately, this demonstration with a specially designed sample showed that the system can simultaneously identify where different elements are located, how atoms are arranged, and how the material is structured.

While conducting the four techniques separately would have taken many hours or even days at separate instruments, the researchers accomplished their experiments in just about six hours.

With new support from NSUF, the researchers are already working to reduce this time to less than 30 minutes by upgrading the setup with next-generation instruments that are even faster and more efficient for data collection.

“This order of magnitude improvement will enhance the experimental throughput by increasing the number of researchers who can come use this tool and the amount of data we can generate, ultimately contributing to the Genesis Mission,” said Ghose, referring to DOE’s Genesis Mission, which aims to double the productivity of research by integrating scientific datasets with the world’s best supercomputers, experimental facilities, and AI systems.

Notably, nuclear science is not the only field that will benefit from this first-of-its-kind X-ray imaging tool. Materials scientists have already used the setup to probe the internal structure of porous materials that can be used for water remediation and energy technologies. Additional studies characterizing batteries as they charge and discharge, as well as other materials that typically operate in under extreme conditions, are also underway.

“The new experimental station — and all the research that will be conducted here — would not have been possible without the unique combination of NSLS-II’s capabilities, Brookhaven’s nuclear materials expertise, and the support from NSUF,” Gill said. “Together, we are enabling researchers to study materials for nuclear applications and beyond in ways that were not possible before — and that work will help pave a path toward next-generation nuclear reactors.”

This work is funded by the DOE Office of Nuclear Energy and the DOE Office of Science.

Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit science.energy.gov.

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