Discovery of Nuclides Project
At the core of each atom is the atomic nucleus (also called nuclide), which consists of neutrons and protons. The number of protons defines the chemical element (for example 6 for carbon and 8 for oxygen). Each element can contain different number of neutrons; these different types of nuclides of an element are called isotopes. The Discovery of Nuclides Project documents the discovery of all isotopes.
Background
In 2007, Professor Michael Thoennessen and a group of undergraduate students began to document the discovery of all isotopes. In contrast to the discovery of a new element, the first observation of a new isotope is not as well defined.
For each isotope, they wrote a brief paragraph describing the discovery, including the authors, institution, year, and method of discovery. The paragraph included a quote from the original paper and discussed any possible controversies related to the discovery.
These paragraphs were published in a series of papers in the journal Atomic Data and Nuclear Data Tables. The table of the discovery papers lists links to the references for each element. In 2015, a major revision which applied the discovery criteria consistently across the chart of nuclei was published in the book The Discovery of Isotopes. Since then, a few additional reassignments and corrections were made.
Learn about the most recent isotope discoveries on the latest discovered isotopes page, and find articles related to the project posted on the publications page.
Search by element, author, laboratory, and more.
View the chart of nuclides on NuDat, from the National Nuclear Data Center.
News
FRIB will continue to update the project and post the most recent new discoveries here.
Discovery criteria
Learn about the guidelines used to determine the claim of discovery of a nuclide here.
Rankings and search
Tables of the top authors, laboratories, countries, and journals are listed here. With the search feature, one can also look up the isotopes discovered by a specific author, or at specific laboratory and country.
Isomer discovery database
A new database documenting the discovery of all isomers with half-lives longer than 100 ns is now available. Nuclear isomers are two or more metastable states within the same isotope. Search by element, author, laboratory and more here.
Comments and updates
If someone is aware of discoveries not yet listed or would like to comment on a specific assignment, please email nuclides@frib.msu.edu.
If you would like to receive notifications about new isotope discovery papers, please email nuclides@frib.msu.edu.
Downloads
The discovery of isotopes database is a json file and available to download here.
The discovery of isomers database is a json file and available to download here.
Learn more about how this work is supported by the U.S. Department of Energy, Office of Nuclear Physics.
