Researchers from Washington University in St. Louis, Fudan University in China, Western Michigan University, the University of Connecticut, the Chinese Academy of Sciences, and FRIB have found evidence of an extremely unstable nucleus for which more than half of the component particles are unbound, meaning that they are not tightly connected to the dense core of the nucleus. The research team had to carefully sift through a large volume of nuclear-collision data to identify the nitrogen-9 decays. This barely bound nucleus poses a unique challenge to theories of nuclear structure.

Researchers from Washington University in St. Louis, Fudan University in China, Western Michigan University, the University of Connecticut, the Chinese Academy of Sciences, and FRIB may have just spotted the elusive, ephemeral nucleus of nitrogen-9 for the first time. With seven protons and two neutrons, the lopsided atomic nucleus of nitrogen-9 pushes the limits of what can even be considered a nucleus at all. Yet signs of its existence seem to be lurking in years-old data from experiments seeking out a different unusual nucleus, researchers report in the 27 October Physical Review Letters.

SLAC National Laboratory’s newly upgraded Linac Coherent Light Source (LCLS-II) heralds trailblazing research capabilities that could unlock the insights needed to create carbon-neutral steel, more sustainable fertilizer, more efficient hydrogen-powered cars or the next generation of pharmaceuticals, to name a few possibilities. LCLS-II is the result of a decade-long collaboration involving more than 1,400 individuals, including those from Fermilab, Argonne, Jefferson Lab, Berkeley Lab, the Facility for Rare Isotope Beams and Cornell University, according to LCLS-II Director Greg Hays. He also said the collaboration involved partners from outside the United States like Germany, Japan, Switzerland and France.

The nuclear reactions that power stellar explosions involve short-lived nuclei that are hard to study in the laboratory. To solve this challenge, researchers at the Facility for Rare Isotope Beams used a novel technique that combines an Active Target Time Projection Chamber with a magnetic spectrometer. The work has been published in Physical Review Letters.

FRIB will use the $115 million it received through a cooperative agreement with the U.S. Department of Energy Office of Science to fund the High Rigidity Spectrometer project.