The discovery of a new type of atomic nucleus

Researchers at Jyväskylä University’s Accelerator Laboratory in Finland have made the groundbreaking discovery of a new atomic nucleus, 190-Astatine, which is now the lightest known isotope of the rare, rapidly degrading element astatine. The realization of the creation of this new isotope was made possible by the fusion of the 84Sr beam particles with the target silver atoms. The isotope was then determined among the fusion products using RITU backscatter detectors.

In a remarkable scientific discovery, researchers have discovered the lightest and most rapidly degrading isotope of the rare element, astatine. Discovered by MSc graduate Henna Kokkonen as part of her thesis, 190-Astatine has provided important insights into the structure of atomic nuclei and the known limits of matter.

An experiment conducted in the Accelerator Laboratory at Jyväskylä University, Finland, has succeeded in producing a previously unknown atomic nucleus, 190-Astatine, consisting of 85 protons and 105 neutrons. The nucleus is the lightest isotope discovered so far.

Astatine is rapidly hydrolyzed, and therefore a rare element. It is estimated that in the Earth’s crust, there is no more than one tablespoon of astatine. An experiment conducted in the Accelerator Laboratory of Jyväskylä University, Finland, has successfully produced a previously unknown atomic nucleus, 190-Astatine. The new isotope was produced in the fusion of 84Sr beam particles and target silver atoms. Isotope detection between products was done using RITU reflux separator detectors.

PhD researcher Hanna Kokkonen from the Department of Physics, University of Jyväskylä. Credit: Henna Kokonen and Kali Oranen

A new nucleus emits alpha particles

New nuclei decay via alpha decay towards more stable isotopes. Alpha decay is a common decay mode of heavy nuclei.

“Studies of new nuclei are important for understanding the structure of atomic nuclei and the known limits of matter,” says PhD researcher Henna Kokkonen from Jyväskylä University’s Department of Physics.

The study is part of my master’s thesis

A new discovery was made by Henna Kokkonen, who recently graduated with a Master of Science degree. The study was part of a master’s thesis. It is not uncommon for the results of a master’s thesis to be published in a peer-reviewed journal, such as physical review cnot to mention that he is reporting a new peer.

“In my dissertation, I analyzed the experimental data among which the new isotope was found. During my dissertation process and summer internship, I got to know the work of the Nuclear Spectroscopy Group. Now I am very happy to work in the group for my PhD.”

Henna Kokkonen moved five years ago to Jyväskylä from Juva, southeastern Finland, to study physics and is now continuing her studies as a doctoral researcher in Jyväskylä University’s Accelerator Laboratory.

Reference: “Properties of the new α-degenerate isotope ¹⁹⁰In “by H. Koukonen, K. Oranien, J. Ousetalo, S. Eikodt, T. Grahn, PT Greenlees, P. Jones, R. Jolin, S. Gutinen, M. Lino, A-P. Libanen, M. Nieman, J. Bakarinen, P. Raquela, J. Sarin, C. Sholey, J. Sory, and M. Finhart, June 20, 2023, Available here. physical review c.
DOI: 10.1103/PhysRevC.107.064312