Nuclear fusion persists at ultralow energies inside metal foils

Scientists in the United States have discovered that deuterium nuclei fusing with metals like palladium and titanium can continue to fuse even at extremely low energy levels where fusion reactions would typically cease. This phenomenon, observed at collision energies as low as 2 keV, is surprising because fusion reactions generally require higher energies to overcome the repulsive forces between positively charged nuclei.

Researchers from the University of California, Davis, and Lawrence Berkeley National Laboratory found that as the incident energy was reduced, the fusion rate didn't drop as expected, but instead plateaued at lower energies. This unusual behavior suggests that the electrons in the metal and internal defects play a significant role in influencing the fusion process.

Jeremy Munday, a physicist from UC Davis, explains that the metal's electron cloud helps shield the repulsion between nuclei, allowing them to get closer together and facilitating fusion even at low energies.

Although the enhanced fusion rates remain far too small for practical energy generation, the discovery opens up new avenues for research. The results indicate that the material itself, rather than just the temperature, can influence nuclear reactions, leading to a new physical regime in fusion science. Konrad Czerski, a nuclear and medical physics professor at the University of Szczecin, Poland, sees the findings as a welcome confirmation of earlier research and believes this could be the start of a new field focused on enhancing the electron screening effect in nuclear reactions, potentially leading to commercial applications such as compact neutron sources.