Alpha Radiation - Animation Fig 1. Animation showing nucleus simultaneously ejects two neutrons and two protons, which correspond to a helium necleus. Replay animation The unstable nucleus simultaneously ejects two neutrons and two protons, which correspond to a helium nucleus. The emission of gamma photons is a secondary reaction that occurs a few thousandths of a second after the disintegration. Adapted from Radiation (Radior, IAEA, European Commission, CEPN)