Key Stage 5
Meaning
Annihilation is the process in which matter and antimatter interact converting all their rest mass into energy resulting in a pair of gamma ray photons being emitted in opposite directions.
About Annihilation
- Annihilation occurs when particles of matter and antimatter interact at extremely close range.
- During annihilation the total rest mass, as well as the kinetic energy, of the particles is equal to the total energy of the two gamma ray photons.
- In annihilation conservation of momentum is conserved due to the momentum of the two gamma ray photons travelling in opposite directions.
Equation
Assuming both particles are at rest
\(2E_0 = 2hf\)
Where
\(E_0\) = Rest Mass Energy of each particle
\(hf\) = The energy of eachgamma ray photon emitted
\(h\) = Planck's Constant
\(f\) = The frequency of the emitted photon
In the special case that one of the particles is in motion
\(2E_0 + E_k = 2hf\)
Where
\(E_k\) = The kinetic energy of the particle