ON THE PREPARATION OF EFFICIENCY CALIBRATION STANDARDS FOR GAMMA-RAY SPECTROMETERS

A procedure for preparation of low-activity efficiency calibration sta ndards in different geometries and having different densities for gamm a-ray spectrometers has been developed. Natural organic and inorganic materials are used as matrices. The densities of the matrices used var y from 0.4 to 1.5 g/cm(3). The activity distribution homogeneity in th e matrix after preparation and after using them for 9 months was studi ed. The matrix stability to settling down and selfgrinding in the proc ess of continued usage is examined. The standards have been prepared u sing certified mixed-nuclide gamma-ray standard solutions, containing Am-241, Cd-109, Ce-139, Co-57, Co-60, Cs-137, Hg-203, Sn-113, Sr-85 an d Y-88 and mono-nuclide solution containing (210)pb from EUROSTANDARD, traceable to the Czech Metrological Institute. Copyright (C) 1996 Els evier Science Ltd.