Development of a Primary Standard for Calibration of 64Cu Activity Measurement Systems

Abstract

A 64Cu national primary standard was developed by the National Institute for Ionising Radiation Metrology (INMRI) of the ENEA (ENEA-INMRI) using the 4 61552 61538; Liquid Scintillation Spectrometry Method with 3H-Standard Efficiency Tracing, in literature known as CIEMAT/NIST method. The relatively short 64Cu half-life required the work to be performed at the production site. A scientific collaboration between the Institute for Health and Consumer Protection of the EC Joint Research Centre (JRC) in Ispra, where the nuclide is produced by a Scanditronix MC40 Cyclotron, and the ENEA-INMRI was then established. Significant efforts were made to identify and quantify the impurities (61Cu and 65Zn) in the mother solution. To this purpose, a new procedure for determination of pure beta emitter impurities by the CIEMAT/NIST method has been applied. A transfer standard portable well-type ionisation chamber was also calibrated, with minimum uncertainty.