Gamma particles are electromagnetic radiation of high frequency and high energy per photon. Gamma rays are a form of ionizing radiation which are very hazardous to biological systems. They are produced by decay of high energy states of atomic nucleus. However, they can be created by other processes. Gamma radiation can ionizes and pass through matter by three different processes, the Photoelectric effect, Compton scattering and Pair production.
The photoelectric effect occurs when a gamma photon comes in contact with an electron which causes transfer of energy.This transfer of energy causes the electron to be removed from the atom. The photoelectric effect is the mechanism for X-ray and gamma ray photons.
Compton scattering happens when an incident gamma photon loses enough energy to an atomic electron to cause its ejection with the remainder of the original photon’s energy emitted as a new lower energy gamma photon. This new gamma photons emission is in a different direction from that of the incident gamma photon; hence the term scattering. The probability of Compton scattering occurring will decreases with increasing photon energy.
Pair production happens when gamma energies exceeding 1.02MeV. The energy of the photon will be converted into the mass of an electron-positron pair through interactions with the electric field of the nucleus. The mass of these two entirely will then be converted into two gamma photons.
Gamma radiation can have the most damaging effects. It causes damage at a cellular level due to its penetrating abilities. If exposed to gamma radiation, the gamma rays can cause radiation sickness, damage cell’s DNA and increase the incidence of cancer.