The process of annihilation
- When a positron is emitted from a tracer in the body, it travels less than a millimetre before it collides with an electron
- The positron and the electron will annihilate, which means
- their mass is converted into energy
- two gamma rays are produced and move apart in opposite directions
- Annihilation doesn’t just happen with electrons and positrons, it can occur between any particle and its antimatter counterpart
- Annihilation is defined as:
When a particle meets its equivalent antiparticle they are both destroyed and their mass is converted into energy
- As with any collision, mass, energy and momentum are always conserved
Annihilation between an electron and positron
When a positron and electron annihilate, their mass is converted into two gamma-ray photons