Gamma rays are produced when atoms or subatomic particles undergo processes that release very high-energy photons. These processes usually involve changes in the nucleus or extreme high-energy events in the universe.
Main ways gamma rays are produced:
- Radioactive decay (gamma decay)
- Certain unstable atomic nuclei (radioisotopes) release excess energy as gamma rays without changing the number of protons or neutrons.
- Example: Cobalt-60 and Cesium-137 emit gamma rays when they transition to a lower energy state after alpha or beta decay.
- Nuclear reactions
- When nuclei collide or fuse (as in nuclear reactors or nuclear weapons), gamma rays are emitted.
- Example: Nuclear fission of uranium-235 or nuclear fusion in the Sun.
- Particle–antiparticle annihilation
- When a particle (e.g., electron) meets its antiparticle (e.g., positron), they annihilate, converting their mass into gamma-ray photons.
- Cosmic and astronomical events
- High-energy processes in space, such as supernova explosions, neutron star collisions, pulsars, and near black holes, produce intense gamma-ray bursts.
- Subatomic particle interactions
- In particle accelerators or cosmic ray collisions, accelerated particles produce gamma rays through processes like Bremsstrahlung (braking radiation).