← Latest briefing

Science

Nuclear physicists identify magnetic source of unexpected low-energy gamma rays

Experiments at the Facility for Rare Isotope Beams trace the low-energy enhancement phenomenon to internal magnetic transitions during radioactive decay.

The short version

  • Researchers identified that internal magnetic flips in atomic nucleons drive the unexpected excess of low-energy gamma ray emissions during radioactive decay.
  • The findings address a decades-old anomaly known as low-energy enhancement, which had resisted consistent theoretical modeling.
  • Scientists expect the new nuclear data to refine models used in nuclear energy, weapons stockpile assessments, nuclear forensics, and astrophysics.

Key facts

  • A study published in Nature by researchers at the Facility for Rare Isotope Beams (FRIB) and Lawrence Livermore National Laboratory (LLNL) resolved the mechanism behind low-energy enhancement in gamma ray emissions.[ScienceDaily]
  • The experiment isolated two decay states of a radioactive copper isotope transitioning into zinc-70, distinguishing between electric transitions and magnetic transitions.[ScienceDaily]
  • The excess low-energy gamma rays occurred solely during magnetic transitions, where protons and neutrons flip their internal magnetic orientations.[ScienceDaily]
  • Electric transitions involving proton repositioning during decay did not exhibit the low-energy enhancement effect.[ScienceDaily]

What remains uncertain

  • Because the experimental confirmation was performed on a single isotope transition, it remains to be verified how broadly the magnetic mechanism applies across all other unmapped nuclei that exhibit low-energy enhancement.[ScienceDaily]

Sources