Gammakiirgus

Gammakiirgus, also known as gamma radiation, is a form of electromagnetic radiation that originates from the nucleus of an atom. It is the most energetic form of electromagnetic radiation, with wavelengths shorter than X-rays. Gamma rays are produced during radioactive decay, when an unstable atomic nucleus releases energy in the form of photons. This process, called gamma emission, is a way for the nucleus to reach a more stable state.

The penetration power of gamma rays is significant, meaning they can pass through many materials that would stop other forms of radiation, such as alpha and beta particles. This property makes them useful in applications like medical imaging (e.g., PET scans) and cancer therapy, where they can be directed to destroy cancerous cells. However, their high energy also makes them ionizing radiation, capable of damaging living tissue and DNA. Therefore, exposure to high levels of gamma radiation can be harmful.

Sources of gamma radiation include natural radioactive materials found in the Earth's crust and cosmic rays from outer space. Man-made sources include nuclear reactors, X-ray tubes operated at high energies, and certain medical isotopes. Shielding against gamma rays typically requires dense materials like lead or concrete. The intensity of gamma radiation decreases with distance from the source, following the inverse square law.