Promethium - Wikipedia, the free encyclopedia

Promethium - Wikipedia, the free encyclopedia: "Promethium was first produced and characterized at Oak Ridge National Laboratory in 1945 by the separation and analysis of the fission products of uranium fuel irradiated in a graphite reactor. The discoverers proposed the name "prometheum" (the spelling was subsequently changed), derived from Prometheus, the Titan in Greek mythology, who stole fire from Mount Olympus and brought it down to mankind, to symbolize "both the daring and the possible misuse of mankind's intellect." However, a sample of the metal was made only in 1963.

There are three possible sources for promethium: rare decays of natural (primordial) neodymium (producing promethium-150), europium (promethium-147), and uranium (various isotopes). The most stable isotope, promethium-145, has a very low rate of alpha decay, so that the alpha half-life is long enough for the presence of primordial promethium to be theoretically possible; however, this has not been experimentally confirmed. The only isotope used in industry is promethium-147, which is used (as 147Pm2O3) in radioionizators, light producers, and atomic batteries; the last of these are used in guided missiles. Since natural promethium is exceedingly scarce, the element is typically man-made by bombarding uranium-235 (enriched uranium) with thermal neutrons (for promethium-147)." Wikipedia