A new type of atomic nucleus discovered

The nucleus is the lightest isotope of astatine discovered to date.


Researchers have succesfully produced a previously unknown atomic nucleus with 85 protons and 105 neutrons. In an experiment performed in the Accelerator Laboratory of the University of Jyväskylä, Finland, the researchers produced 190-Astatine, the lightest isotope of astatine.

Astatine is a fast-decaying, hence is a rare element. The new isotope was created by fusing 84Sr beam particles with silver target atoms. Using the detectors from the RITU recoil separator, the isotope was found among the products.

The new nuclei decay by alpha decay into more stable isotopes. One typical way that heavy nuclei decay is through alpha decay.

Doctoral Researcher Henna Kokkonen from the Department of Physics, University of Jyväskylä said, “The studies of new nuclei are important for understanding the structure of atomic nuclei and the limits of known matter.”

Henna Kokkonen, who recently graduated Master of Science, said, “In my thesis, I analyzed experimental data among which the new isotope was found. During my thesis process and summer internships, I got to know the Nuclear Spectroscopy group’s work. Now I am very happy to work towards my Ph.D. in the group.”

Journal Reference:

  1. H. Kokkonen et al., Properties of the new α -decaying isotope At190, Physical Review C (2023). DOI: 10.1103/PhysRevC.107.064312