Researchers led by scientists at the Facility for Rare Isotope Beams, or FRIB, say they have identified the source of an unusual burst of low-energy gamma rays from the zinc-70 nucleus, according to ScienceDaily.
The team found that magnetic transitions inside the nucleus are responsible for the signal, resolving a question that has challenged nuclear physicists for years. Their study, published in Nature under the title “Magnetic Character of the Low-Energy Enhancement in 70Zn,” offers a clearer explanation for what scientists call the low-energy enhancement, or LEE.
The work involved an international collaboration from 25 institutions in the U.S., Canada, Italy, Germany, Norway and South Korea, including researchers from several national laboratories such as Lawrence Livermore, Los Alamos, Lawrence Berkeley and Pacific Northwest National Laboratories.
According to the researchers, understanding the enhancement matters beyond the nucleus itself because it can affect neutron-capture reaction rates. Those reactions are important in the creation of heavy elements during extreme cosmic events such as supernovae and neutron star mergers.
The team focused on zinc-70 by studying two forms of its parent nucleus, copper-70, and using FRIB’s Low Energy Beam and Ion Trap, or LEBIT, to produce exceptionally pure beams. Researchers said the method helped provide strong evidence for the magnetic origin of the gamma-ray signal and could support future studies of other nuclei.
