Properties of Radiation

Properties	Alpha Radiation (α)	Beta Radiation (β)	Gamma Radiation (γ)
Nature	2 Protons and Neutrons	β+ = Electron β- = Positron	Photon of Energy of the Order of MeV
Range in Air	Fixed Range (Depends on Energy which can be up to 100mm	Range up to about 1m	Follows the Inverse Square Law (See Equations)
Deflection in a Magnetic Field	Easily Deflected	Opposite Direction to α particles and more easily deflected	Not Deflected
Absorption	Stopped by Paper or Thin Metal Foil	Stopped by Approximately 5mm of Aluminium	Stopped by Several Centimetres of Lead
Ionisation	Produces about 104 Ions per mm in Air at Standard Pressure	Produces about 100 Ions per mm in Air at Standard Pressure	Very Weak Ionising Effect
Energy of Each Particle/Photon	Constant for a given Source	Varies up to a Maximum for a given Source	Constant for a given Source
Danger Inside and Outside of the Body	Inside: Dangerous Outside: Less Dangerous than β and γ	Inside: Less Dangerous than α Outside: Dangerous	Inside: Less Dangerous than α Outside: Dangerous

©2011 Grant Dwyer