METHOD OF PRODUCING GAMMA-RAY SOURCES BASED ON Se RADIONUCLIDE FOR GAMMA-RAY FLAW DETECTION Russian patent published in 2012 - IPC G21G4/04 

FIELD: physics.

SUBSTANCE: method of producing gamma-ray sources based on the selenium-75 radionuclide for gamma-ray flaw detection involves sealing the workpiece of an activated core made from highly enriched (not less than 96%) selenium-74 into an ampoule, exposing the obtained ampoule in an atomic reactor and sealing the exposed ampoule into a capsule. The solid monolithic workpiece of the exposed core, made with density corresponding to the theoretical density, is put into a fully corresponding disciplining volume. The cover of the ampoule is sealed via laser welding with simultaneous heat removal, and the outer surface of the ampoule is subjected to sputtering, followed by sealing and hardening with a metal. During exposure in the reactor, metal isotopes are formed, having gamma-ray energy less than that of selenium-75 gamma-radiation with half-life of less than 1 hour, the thickness of the coating layer of which provides compensation of excess pressure formed inside the sealed ampoule during exposure. Exposure is carried out in a reactor thermal neutron flux with density of not less than 10¹⁵ N/cm² under conditions which enable to achieve maximum specific activity of selenium-75 (not less than 1250 Ci/g), and sealing is carried out via argon-arc welding in the working capsule.

EFFECT: invention increases resolution, cuts inspection time and increases sensitivity and widens functionalities of the apparatus.

3 cl