Yttrium-90 Decay Scheme

Yttrium-90 (90Y) is a beta (electron) emitter with an average energy of 0.9267 MeV and a half-life of 2.67 days. Over 90% of emitted energy is absorbed within 5.3mm and the maximum range of emitted electons is 11mm. Y-90 is most commonly used in radiation therapy as the source in microsphere liver treatments.

Quick facts

  • Half life: 2.67 days
    • Decays approximately 1% per hour
  • Decay mode: β
  • Beta energy: 0.9267 MeV (mean)