Nanomaterials offer a safer, faster way to develop devices for use in nuclear threat detections
Special nuclear materials like enriched uranium and plutonium pose a serious threat due to their potential use in nuclear weapons. Yet detecting them in a timely manner remains a significant challenge for global security. These materials emit weak radiation that can be easily shielded, making their presence difficult to trace with conventional radiation detectors. However, detecting the neutrons they emit or produce when interrogated with radiation sources offers a promising solution. The EU-funded NASCAR project aimed to create a new type of detector capable of sensing these neutrons effectively. Instead of relying on bulky or hazardous technologies, the team turned to nanotechnology – specifically, zinc oxide (ZnO) nanorods doped with the isotope lithium-6. The project was coordinated by Professor Murat Kurudirek in collaboration with Prof. Dr. Paul Sellin from the University of Surrey (UK), Prof. Dr. Anna Erickson, and Emeritus Prof. Dr. Nolan Hertel from the Georgia Institute of Technology (USA).
A better way to detect nuclear threats
Conventional neutron detectors often use rare or toxic gases such as helium-3 or boron trifluoride. These gaseous materials are expensive, sometimes dangerous, and the systems using them are difficult to scale. NASCAR researchers designed an alternative detector material based on ZnO nanorod arrays grown using a low-cost, environmentally friendly technique. “A low-cost solution growth technique, which does not require single-crystal or conductive substrates and high temperatures to operate, is used in this project,” explains Murat Kurudirek, NASCAR project researcher. The method allows for fine control of nanorod shape and size while keeping costs down and avoiding the need for complex equipment. The detectors are made by growing vertically aligned, tapered ZnO nanorods – tiny crystalline rods that efficiently guide scintillation light produced in the rods by radiation interactions toward a sensor. This structure improves spatial resolution and reduces photon loss.
Enhancing neutron sensitivity with lithium-6
Thermal neutrons are difficult to detect without a material that can effectively capture them. For this reason, the project incorporated lithium-6, a stable isotope with a strong interaction with low-energy or thermal neutrons. “When integrated with 6Li, which has a very high thermal neutron interaction cross-section, ZnO becomes highly sensitive to thermal neutrons through the n-alpha (n,α) reactions,” says Kurudirek. The alpha particles and tritons from the neutron-lithium interaction then trigger light emissions in the ZnO structure. The team developed lithium-incorporated nanorod arrays that showed strong sensitivity to thermal neutrons in lab tests. Their promising results are now being prepared for scientific publication.
From lab innovation to real-world impact
Beyond lab performance, the detectors offer features suited for real-world use. They are compact, cost-effective, and fast, making them ideal for mobile detection units and real-time monitoring systems in border control, cargo inspection, and nuclear non-proliferation. “The tapered ZnO nano arrays can help the light collection in the structure and thus enhance the scintillation efficiency,” says Kurudirek. Their unique design helps guide light directly into the detector, improving spatial resolution and reducing signal loss, two major challenges in nuclear detection technologies. Professor Murat Kurudirek, now based at Atatürk University in Turkey, plans to build on the NASCAR experience by applying for competitive grants to establish an international research group. His goal is to develop new generations of affordable, accessible, and environmentally friendly nuclear detection technologies. By laying the foundation for next-generation detectors, the NASCAR project has opened a scalable pathway to high-performance neutron detection. This marks an important step toward improving public safety and global nuclear security.
Keywords
NASCAR, lithium-6, nanotechnology, ZnO nanorods, neutron detection, public safety
