A novel apparatus at the U.S. Department of Energy’s (DOE) Argonne National Laboratory has made extremely precise measurements of unstable ruthenium nuclei. The measurements are a significant milestone in nuclear physics because they closely match predictions made by sophisticated nuclear models.

“It’s very difficult for theoretical models to predict the properties of complex, unstable nuclei,” said Bernhard Maass, an assistant physicist at Argonne and the study’s lead author. “We have demonstrated that a class of advanced models can do this accurately. Our results help to validate the models.”

Validating the models can build trust in their predictions about astrophysical processes. These include the formation, evolution and explosions of stars where elements are created.