Alfasugárzás

Alfasugárzás, also known as alpha radiation, is a form of particle radiation that consists of helium nuclei. These nuclei are composed of two protons and two neutrons, giving them a positive charge of +2e and an atomic mass of approximately 4 atomic mass units. Alpha particles are emitted from the nucleus of an atom during radioactive decay, a process known as alpha decay. This typically occurs in heavy, unstable isotopes.

When an alpha particle is emitted, the parent nucleus loses two protons and two neutrons, resulting in a transformation into a different element with a lower atomic number and mass number. For example, the alpha decay of Uranium-238 produces Thorium-234.

Despite their relatively large mass and charge, alpha particles have a very short range and low penetrating power. They can be stopped by a sheet of paper, a few centimeters of air, or the outer layer of human skin. For this reason, alpha emitters pose little external hazard. However, if an alpha-emitting substance is ingested or inhaled, the alpha particles can cause significant damage to internal tissues due to their high linear energy transfer (LET). This means they deposit a large amount of energy in a very small volume, leading to intense ionization and potential cellular damage. Radon gas, an alpha emitter, is a well-known example of an internal hazard.