BetaEmitter

BetaEmitter is a term used to describe a radionuclide or source that decays by emitting beta particles as part of its radioactive decay. Beta emission occurs when a neutron converts to a proton with the emission of an electron (beta-minus) or a proton converts to a neutron with the emission of a positron (beta-plus). Some beta emitters also produce gamma rays during subsequent transitions, which can influence shielding and detection requirements.

Common beta emitters include tritium (H-3), carbon-14, strontium-90, yttrium-90, phosphorus-32, and iodine-131. These nuclides vary widely in half-life and radiation energy. Beta-minus emitters eject electrons with energies ranging from a few keV to several MeV, while beta-plus emitters release positrons that ultimately annihilate with electrons, producing gamma rays. The penetrating power and tissue range of beta particles depend on their energy, typically from millimeters to a few centimeters in biological material.

Applications of beta emitters span medicine, science, and industry. In medicine, beta emitters are used for radiopharmaceutical therapies (for example, yttrium-90 microspheres and iodine-131 for thyroid conditions) and as tracers in research. In dating and biology, carbon-14 and phosphorus-32 are used as tracers in experiments. Beta emitters are also employed in industrial gauging and calibration devices.

Safety and regulation emphasize containment, shielding, and monitoring to prevent unintended exposure. Shielding is usually made of plastic or other lightweight material, with containment plans to prevent ingestion or inhalation. Proper licensing, handling procedures, and waste disposal are required, reflecting the radiological and chemical hazards associated with beta-emitting sources.