Iridium192

Iridium-192 (Ir-192) is a radioactive isotope of iridium with a half-life of 73.83 days. It decays by beta minus emission to platinum-192 and emits gamma radiation, producing several gamma lines that make it useful as a high-energy gamma source. Because of its relatively short half-life and strong gamma emission, Ir-192 is used in sealed sources for industrial radiography and certain cancer therapies.

Most Ir-192 is produced by neutron activation of stable Ir-191 in nuclear reactors. The resultant Ir-192 is incorporated into sealed metal capsules for use in radiography or afterloading brachytherapy. Handling requires licensing; sources are designed to contain radiation and prevent leaks; shielding typically uses lead or tungsten.

It is widely used in nondestructive testing to inspect welds and metal joints in pipelines, aircraft, and castings. In medicine, Ir-192 sources have been used for brachytherapy, delivering localized radiation to tumors in intracavitary or interstitial applications, though newer isotopes and methods have emerged. The source strength is described by activity in curies or becquerels and is regulated.

Because Ir-192 emits penetrating gamma radiation, proper shielding, handling protocols, and regulatory controls are required. Spent or leaking sources are returned to suppliers or disposed of by licensed facilities. Decay storage may be used when turnover allows.