Bi214

Bi-214 is a radioactive isotope of bismuth with atomic number 83 and a mass number of 214. It occurs in the uranium-238 decay chain (and in the downstream radon-222 decay series) as a short-lived daughter nuclide produced by beta decay of Pb-214, and it subsequently decays to Po-214.

Bi-214 decays predominantly by beta minus emission to Po-214, with a half-life of about 19.9 minutes. The beta decay has an endpoint energy near 3.27 MeV. Bi-214 is followed by Po-214, which decays extremely rapidly by alpha emission to Pb-210, with a half-life of about 164 microseconds. Through its decay, Bi-214 emits gamma rays as part of its de-excitation cascade; notable lines include energies around 609 keV and 1764 keV, among others. These gamma emissions make Bi-214 a common feature in gamma spectrometry.

Occurrence and use: Bi-214 is not a primordial nuclide and is instead produced transiently in uranium-238 and thorium-232 decay chains, particularly in environments containing radon gas and its progeny. Because of its characteristic gamma emissions, Bi-214 is widely used in radiation monitoring and as a calibration standard in gamma-ray spectroscopy. Its presence in environmental samples is often an indicator of radon-222 decay products.

Safety and handling: As a beta-emitting and gamma-emitting isotope, Bi-214 poses radiological hazards through external gamma exposure and inhalation or ingestion of contaminated materials. Proper shielding, containment, and monitoring are standard in settings where exposure to uranium-238 decay products is possible.