A rendering of Nitrogen-9 (N-9). Credit: Washington University in St. Louis
A researcher from Washington University in St. Louis recently described a new light isotope of nitrogen, called Nitrogen-9. Nitrogen-9 is the first known instance in which a nucleus decays by emitting five protons from its ground state.
In the research, published in Physical Review Letters, researchers presented their findings on the new isotope resulting from experiments conducted at the National Superconducting Cyclotron Laboratory. Nitrogen-9 consists of five unbound protons surrounding an alpha particle, their mutual interactions hold together this assemblage. The unbound protons are liberated in steps, a single proton escapes first followed by subsequent pairs of protons.
"The decay of Nitrogen-9 is like opening a set of nesting dolls; each decay reveals another nuclide, which also decays by the emission of a single or a pair of protons," said Robert Charity, a research professor of chemistry in Arts & Sciences at Washington University in St. Louis. "The existence of such an exotic system is a good test of the quantum mechanics of open or unbound many-body systems."
Along with these findings, the researchers also published a paper in Physical Review C outlining steps to analyze experiments used to yield results on exotic nuclei.
"The elements we have around us are made via a set of mechanisms that work through intermediates that we do not have around us," said Lee Sobotka, professor of chemistry. "These intermediates are unstable and often have highly unusual neutron-to-proton ratios. Our work involves both reconstructing the structure of, and reactions producing, such nuclei."