Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.

A beam of ALPHA PARTICLES.

Synonyms: Particles, Alpha, Particle, Alpha, Alpha Particles, Ray, Alpha, Radiation, Alpha, Alpha Particle, Rays, Alpha, Alpha Rays, Alpha Radiation, Alpha Ray