lonising Radiation

• Ionising Radiation


  Three types: alpha, beta and gamma
• Alpha Particles


  • Helium nuclei
  • Strongly ionising
  • Don't penetrate far into materials
  • Absorbed by a sheet of paper
  • Used in smoke detectors to ionise air particles
• Beta Particles


  • High-speed electrons
  • Moderately ionising
  • Penetrate moderately far into materials
  • Absorbed by a sheet of aluminium
  • Used to test thickness of metal sheets
• Gamma Rays


  • Electromagnetic waves with short wavelength
  • Weakly ionising
  • Penetrate far into materials
  • Absorbed by thick sheets of lead or concrete
• Alpha particles are more ionising than beta particles
• Gamma rays are electromagnetic waves released by the nucleus