US nuclear fusion breakthrough: Solid materials found to elevate low-energy reaction rates

Researchers standing next to the experimental setup at UC Davis.Berkeley Lab Scientists at UC Davis and Lawrence Berkeley National Laboratory have discovered that surrounding materials can dramatically increase how often nuclear fusion happens at low energies. The study opens up an entirely new area of research called materials-driven fusion. “Instead of designing materials just to survive the harsh conditions of fusion, researchers might be able to design materials that boost the reaction in specific conditions, similar to the way catalysts speed up chemical processes,” said the team in a press release. To test how host materials affect fusion, the team packed deuterium—a heavy form of hydrogen—into thin metal foils made of titanium and palladium. They used two different techniques to load the deuterium into the metals. Next, they fired a beam of deuterium ions directly at the loaded foils across a range of energy levels and measured how often fusion happened compared to reactions in open space without any surrounding metal. Standard physics theory predicts that fusion rates drop off sharply when collision energies fall below 2.5 kiloelectronvolts (keV). However, the team’s measurements showed an unexpected result: at these lower energies, the fusion rate leveled off into a plateau instead. In certain metal samples, fusion occurred about a quintillion times—a 1 followed by 18 zeroes—more often than in reactions without a host material. Big jump in reaction rates This big jump in reaction rates comes down to the subatomic structure of the host metals. Electrons inside the metal, along with tiny defects in the foil structure, act like a shield around the positively charged deuterium nuclei. “The electrons and defects within the material might partially shield repulsive electrostatic forces between deuterium nuclei, making it easier for them to get close together and fuse,” explained the researchers. By tweaking a material’s internal structure, electron behavior, and overall mix, researchers can influence how easily these nuclear reactions occur. Beyond generating power, controlling low-energy fusion produces subatomic particles called neutrons. “If we understand this effect better, it opens the door to engineering new materials that would affect the fusion rate under certain conditions,” concluded Arun Persaud, head of the Fusion Science & Ion Beam Technology group in Berkeley Lab’s Accelerator Technology & Applied Physics (ATAP) Division. “Someday future progress might enable more compact and efficient neutron generators, which have all kinds of applications, like cargo screening, planetary science, and medical therapy and imaging.” Bridging fusion with predictive modeling The team’s work establishes a reliable, repeatable way to test how solid metals affect nuclear interactions, creating a fresh link between fusion science, materials science, and chemistry. This discovery connects with work happening at Ames National Laboratory to better understand how materials handle nuclear operations. Scientists there are currently expanding an artificial intelligence tool called DuctGPT to improve predictions about how materials behave inside active fusion energy systems. Running a fusion system subjects surrounding parts to harsh operational conditions, including intense heat, radiation, and mechanical stress. By adding new data and models to DuctGPT, researchers can better predict how different materials hold up under these extreme forces over time.Recommended ArticlesGet the latest in engineering, tech, space & science - delivered daily to your inbox.An active and versatile journalist and news editor. He has covered regular and breaking news for several leading publications and news media, including The Hindu, Economic Times, Tomorrow Makers, and many more. Aman holds expertise in politics, travel, and tech news, especially in AI, advanced algorithms, and blockchain, with a strong curiosity about all things that fall under science and tech.