Landmark Experiment Reveals New Isotopes of Rare-Earth Elements and Advances Understanding of Neutron-Rich Nuclei
In a groundbreaking experiment, physicists at Michigan State University have made a significant discovery that could revolutionize our understanding of atomic nuclei and the formation of new elements. Led by Oleg Tarasov, the team successfully broke apart the nuclei of platinum, leading to the identification of new isotopes of rare-Earth elements thulium, ytterbium, and lutetium. This achievement not only sheds light on neutron-rich nuclei but also provides valuable insights into the processes that occur during the collision of neutron stars.
The experiment was made possible by the state-of-the-art Facility for Rare Isotope Beams (FRIB) at Michigan State University. This facility, which conducted its first experiment in June 2022, has proven to be a powerful tool for scientific exploration. By fragmenting atomic nuclei using a heavy-ion accelerator, researchers were able to observe never-before-seen ratios of particles within atomic nuclei.
To understand the significance of this discovery, it is essential to grasp the concept of isotopes. While all forms of an element have the same number of protons, the number of neutrons can vary. These variations give rise to different isotopes of an element. Some isotopes are highly unstable and decay rapidly, while others remain stable. By studying these isotopes and their behavior, scientists can gain insights into the processes that create elements and estimate their abundances across space and time.
In this experiment, Tarasov and his team used an isotope of platinum called 198Pt, which has 120 neutrons. By introducing this heavier isotope into the FRIB, they were able to observe how the nucleus fragments differently. The researchers discovered new isotopes such as 182Tm and 183Tm for thulium, 186Yb and 187Yb for ytterbium, and 190Lu for lutetium. These isotopes had varying numbers of neutrons compared to their standard counterparts.
What makes this experiment particularly significant is that these new isotopes were observed in multiple runs of the accelerator. This demonstrates the capability of FRIB to study the synthesis of neutron-rich isotopes of heavy elements that have previously been challenging to create and detect. By delving into these unexplored regimes, scientists can gain a deeper understanding of how violent cosmic events, such as supernovae and neutron star collisions, give rise to the heaviest elements in the Universe.
One of the nucleosynthesis processes observed in neutron star collisions is the rapid neutron-capture process (r-process). During this process, atomic nuclei rapidly capture free-floating neutrons, leading to the formation of heavier elements. Gold, strontium, platinum, and other heavy metals are products of the r-process. The team’s experiment has brought us one step closer to replicating this process in the laboratory, providing us with a valuable tool to study one of the most fascinating phenomena in the Universe.
“The unique capabilities of FRIB, including very intense primary beams at energies exceeding those that were available at the National Superconducting Cyclotron Laboratory, make it an ideal facility for exploring the region around neutron number N = 126 and beyond,” the researchers write. This highlights the immense potential of FRIB in advancing our knowledge of nuclear physics, astrophysics, and the fundamental properties of matter.
The research conducted by Tarasov and his team has been published in Physical Review Letters, marking a significant milestone in our understanding of atomic nuclei and the formation of new elements. With further advancements in this field, we may unlock even more secrets about the origins of our Universe and the processes that shape it. The journey towards unraveling the mysteries of neutron-rich nuclei and cosmic nucleosynthesis continues, fueled by the remarkable discoveries made at Michigan State University’s FRIB.