Plans to deliver the first-ever precision measurements of some of the rarest and most unstable atomic nuclei could reshape our understanding of nuclear structure and how chemical elements are formed under extreme cosmic events, such as supernovae, neutron-star collisions and X-ray bursts. The University of Surrey is working with researchers in Japan to develop state-of-the-art instruments capable of measuring previously inaccessible isotopes – forms of matter that exist only fleetingly at the edges of nuclear stability.

The project has received £215,100 from the Royal Society’s International Science Partnership Fund and is a collaboration with Japan’s Kyushu University and Radioactive Isotope Beam Factory (RIBF) at the RIKEN laboratory – a world-leading facility where the most intense exotic beams can be created for experiments.

The research will investigate fundamental properties of unstable atomic nuclei, with a focus on both neutron-rich and neutron-deficient isotopes. These nuclei do not occur naturally on Earth and can only be created for brief moments in advanced physics laboratories. Measuring how heavy they are (their mass) and how quickly they decay (their half-life) will provide invaluable insights to refine theoretical models in nuclear structure and help to understand the origin of chemical elements in nuclear astrophysics.

Dr Ragandeep Singh Sidhu, Future Fellow at the University of Surrey’s School of Mathematics and Physics, and project co-lead, said:

“These extremely rare isotopes are among the most difficult atomic nuclei to study, but they hold crucial clues about how nuclear matter behaves at its limits. Measuring their mass and half-lives for the first time will allow us to significantly improve the models used to understand both atomic nuclei and the cosmic processes that create the heaviest elements in the universe. This work would not be possible without close collaboration with our partners in Japan and access to world-leading facilities at RIBF, RIKEN.”

Experiments will be carried out at the Rare-Radioactive Isotope Ring (R3) at RIBF, RIKEN – a unique facility capable of storing and repeatedly observing these short-lived nuclei. Using state-of-the-art detection techniques, researchers will be able to access regions of the nuclear landscape that have never been experimentally measured before.

The Surrey team will play a central role in the project, leading the development and testing of advanced detector and data-acquisition systems in the UK before the experimental campaign starts in Japan.

The three-year project will also strengthen international collaboration between the UK and Japan, supporting the development of advanced experimental tools and helping to maintain the UK’s position at the forefront of nuclear physics research.

Dr Masaomi Tanaka, Assistant Professor at Kyushu University and project co-lead, said:

“One of the most exciting aspects of this project is the opportunity to study how nuclear shells behave in some of the heaviest and most neutron-rich nuclei ever measured. For some of these isotopes, we currently have almost no experimental data, so these measurements will directly challenge and improve our understanding. Through this collaboration, we aim to map the nuclear landscape in new and previously inaccessible detail.”

[ENDS]