Radiobiology > Physical Processes > Quanta > Alpha Particles

Alpha Particles

Alpha particles…

  • Are large and positively charged
  • Tend to cause ionizations and lose energy over a very short distance
  • Are composed of two protons and two neutrons (i.e. a naked helium nucleus)
  • Large size + relatively high charge prevent deep penetration of matter (blocked by dead skin or paper)
  • Chronic exposure to inhaled alpha particles is a lung cancer risk
  • Are important in the uranium decay series, of which radon is a product

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