Outside the Facility for Rare Isotope Beams (FRIB) on March 21, 2023.
An international research team working at the Facility for Rare Isotope Beams, or FRIB, at Michigan State University has successfully produced, separated, and identified five new isotopes that had never been seen on the surface of the Earth.
The isotopes — identified as thulium-182, thulium-183, ytterbium-186, ytterbium-187 and lutetium-190 — were reported Feb. 15 in the scientific journal Physical Review Letters. Their discovery was the result of a collaborative effort between MSU, the Institute for Basic Science in South Korea and Japan’s Institute of Physical and Chemical Research.
MSU operates FRIB as a user facility for the U.S. Department of Energy Office of Science, meaning it receives federal funding and is available for external use to "advance scientific and or technical knowledge."
Like everything in the physical world, isotopes are a type of atom. While atoms belonging to different elements differ based on their unique configuration of protons and electrons, isotopes introduce variety among atoms belonging to the same element by retaining the same number of protons and electrons but having varying numbers of neutrons.
These subatomic differences give isotopes unique physical properties that are of interest to scientists. However, some isotopes do not appear naturally on Earth, necessitating specialized equipment like that found at FRIB to create them.
“Some isotopes are heavier, some isotopes are a lot lighter, some isotopes are radioactive, some isotopes behave very differently in the center of a star than other isotopes,” said Bradley Sherrill, University Distinguished Professor in MSU’s College of Natural Science and head of the Advanced Rare Isotope Separator department at FRIB. “The common (isotopes) you find in nature, you can buy somewhere. But for the special ones that you can’t find on Earth, you have to come to a research facility like FRIB.”
These five isotopes represent the first batch of new isotopes created at FRIB. However, Sherrill estimated that FRIB could eventually create up to 1,000 new isotopes. The significance of this discovery, Sherrill noted, is not about the isotopes themselves but rather that FRIB has now demonstrated the capability to create new isotopes, opening the door to future scientific discovery.
“This is the demonstration now that we’re already starting to (make isotopes),” Sherrill said. "We’re already starting on this journey of exploring isotopes that can exist but were never before made.”
Ultimately, Sherrill said, scientists are interested in FRIB’s potential to create isotopes that play a role in the synthesis of “heavy elements” such as uranium and lead. These elements are thought to be created when neutron stars collide in space and are scattered across the universe, some of which can be found on Earth.
“(This discovery) demonstrates that FRIB will be able to make some significant number of the important isotopes that would be relevant to model astrophysical environments, like when neutron stars collide,” Sherrill said. “We’d like to understand that so we want to try to create the conditions that existed there.”
Sherrill said he was excited about the potential being unlocked through FRIB, adding that “it’s the culmination of a dream for a lot of people.”
“I’m thrilled that we have this capability at MSU to be able to do things that no one could ever do before,” Sherrill said. “I’m very happy that we can provide this service to the world.”
