Materials surrounding a fusion reaction can dramatically increase how often it occurs

Materials surrounding a fusion reaction can dramatically increase how often it occurs
Schematic of the dual-chamber configuration. Credit: Nature Communications (2026). DOI: 10.1038/s41467-026-74421-1

Fusion at high temperatures powers the sun and, if harnessed, could provide a potential source of energy here on Earth. But controlling fusion reactions has other benefits. The process also generates subatomic particles called neutrons that are used in a range of applications spanning medicine, research and national security.

Scientists at the University of California, Davis, and the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have found that the materials surrounding a fusion reaction can dramatically increase how often it occurs, particularly at low energies where fusion is rare. Their study is published in Nature Communications. The study's first author is Micah Karahadian, a doctoral candidate in Munday's lab at UC Davis.

Their approach establishes a way to study and engineer nuclear reactions within solid materials, opening a new field of "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 under specific conditions, similar to the way catalysts speed up chemical processes.

"It gives you a new knob to turn that you didn't have before," said co-author Arun Persaud, head of the Fusion Science & Ion Beam Technology group in Berkeley Lab's Accelerator Technology & Applied Physics Division (ATAP). "If we understand this effect better, it opens the door to engineering new materials that would affect the fusion rate under certain conditions. 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."

In the experiment, researchers used two different methods to pack deuterium—a heavy form of hydrogen often used in fusion—into thin foils of palladium and titanium. They then fired a beam of deuterium ions at the foils at different energies and measured how often fusion occurred. They compared the rates from the different materials and methods with the "bare" fusion reaction (not in a material).

When it comes to fusion, materials matter
UC Davis Professor Jeremy Munday, left, and doctoral candidate Micah Karahadian, who led the study, stand next to the experimental setup at UC Davis. Credit: Marina Leite, UC Davis

A surprising fusion plateau

The team found that fusion rates depended on how the deuterium was loaded into the metal foils. The biggest effect was at the lowest energies, below 2.5 kiloelectronvolts (keV), where theory predicts fusion rates drop off sharply. Instead, researchers found a surprising plateau: Some samples showed elevated fusion rates roughly a quintillion times higher than bare fusion reactions. (A quintillion is a 1 followed by 18 zeros.)

Researchers aren't exactly sure why that's happening, though they have some ideas and ways to test them. 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. Tuning the electronic structure, defects and composition of materials could help make nuclear reactions happen more readily.

"It comes down to better understanding the mechanism so that we can try to enhance it," said corresponding author Jeremy Munday, a UC Davis professor in the College of Engineering. "We've seen that we can increase fusion rates, but what is the limit? Can we bring it to lower temperatures or energies? There's obviously a lot of interest and excitement about fusion, so if there's something we can learn about the physics at these lower energy scales, maybe there's something we can translate to other areas of nuclear science."

The team plans to explore a wider range of materials and continue probing the unexpected fusion plateau at lower energies. Their work establishes a reproducible experimental platform to study how solid materials influence nuclear reactions, creating a new area of research that links fusion science with materials science and chemistry.

"The work shows conclusively that the material environment where fusion occurs at low temperatures is an active participant rather than a passive container," said co-author Cameron Geddes, director of ATAP. "That adds a new dimension to fusion research."

Publication details

Micah E. Karahadian et al, Enhanced nuclear fusion in the sub-keV energy regime, Nature Communications (2026). DOI: 10.1038/s41467-026-74421-1

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Citation: Materials surrounding a fusion reaction can dramatically increase how often it occurs (2026, July 23) retrieved 24 July 2026 from https://phys.org/news/2026-07-materials-fusion-reaction.html

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