Chinese scientists create 2 never-before-seen atomic nuclei

Scientists in China have created two new atomic nuclei that have never been observed before: Berkelium-235 and Americium-231. Their groundbreaking work pushes the boundaries of the periodic table and helps us better understand the building blocks of matter.

The team, from the Institute of Modern Physics at the Chinese Academy of Sciences, used a powerful particle accelerator in Lanzhou City, the capital of northwest China's Gansu Province, to perform the feat. Their results were published in the journal Physics Letters B.

How to make a new nucleus

Creating a new isotope is like playing high-speed cosmic billiards. The researchers used the Chinese Accelerator Facility for Exotic Nuclei (CAFE2) to fire a high-intensity beam of Argon-40 ions at a target made of Gold-197.

When these atoms collided at just the right speed, they fused together, creating new, heavier nuclei. These products were then filtered and identified using a sophisticated "separator" called SHANS2, which can detect even a single atom based on its energy, position, and timing.

The research team determined that Americium-231 is the "daughter" nucleus produced when Berkelium-235 undergoes radioactive decay, with a half-life of about 75 seconds.

Fine-tuning physics theories

How accurate are our theoretical models that predict nuclear behavior? Interestingly, the team found that existing mass models overestimated the decay energies for these extremely neutron-deficient elements. That mismatch gives theorists a clear signal that their models need fine-tuning.

For now, Berkelium-235 and Americium-231 exist only for seconds inside a detector. But their brief existence has already taught us something new about the limits of matter.