Just a few hundred feet from where we are sitting is a large metal chamber devoid of air and draped with the wires needed to control the instruments inside. A beam of particles passes through the interior of the chamber silently at around half the speed of light until it smashes into a solid piece of material, resulting in a burst of rare isotopes.
This is all taking place in the Facility for Rare Isotope Beams, or FRIB, which is operated by Michigan State University for the U.S. Department of Energy Office of Science. Starting in May 2022, national and international teams of scientists converged at Michigan State University and began running scientific experiments at FRIB with the goal of creating, isolating and studying new isotopes. The experiments promised to provide new insights into the fundamental nature of the universe.
We are two professors in nuclear chemistry and nuclear physics who study rare isotopes. Isotopes are, in a sense, different flavors of an element with the same number of protons in their nucleus but different numbers of neutrons.
The accelerator at FRIB started working at low power, but when it finishes ramping up to full strength, it will be the most powerful heavy-ion accelerator on Earth. By accelerating heavy ions – electrically charged atoms of elements – FRIB will allow scientists like us to create and study thousands of never-before-seen isotopes. A community of roughly 1,600 nuclear scientists from all over the world has been waiting for a decade to begin doing science enabled by the new particle accelerator.
The first experiments at FRIB were completed over the summer of 2022. Even though the facility is currently running at only a fraction of its full power, multiple scientific collaborations working at FRIB have already produced and detected about 100 rare isotopes. These early results are helping researchers learn about some of the rarest physics in the universe.
Rare isotopes are radioactive and decay over time as they emit radiation – visible here as the streaks coming from the small piece of uranium in the center.
What is a rare isotope?
It takes incredibly high amounts of energy to produce most isotopes. In nature, heavy rare isotopes are produced during the cataclysmic deaths of massive stars called supernovas or during the merging of two neutron stars.
To the naked eye, two isotopes of any element look and behave the same way – all isotopes of the element mercury would look just like the liquid metal used in old thermometers. However, because the nuclei of isotopes of the same element have different numbers of neutrons, they differ in how long they live, what type of radioactivity they emit and in many other ways.
For example, some isotopes are stable and do not decay or emit radiation, so they are common in the universe. Other isotopes of the very same element can be radioactive so they inevitably decay away…