Measurement of Radionuclide Activities Induced in Target Components of an IBA CYCLONE 18/9 by Gamma-Ray Spectrometry with HPGe and LaBr3:Ce Detectors

Abstract

The activity values of gamma-emitting radionuclides in some activated target components of an IBA CYCLONE 18/9 cyclotron were evaluated by high resolution gamma-ray spectrometry with High Purity Germanium (HPGe) and Lanthanum bromide (LaBr3:Ce) detectors. The use of a LaBr3:Ce scintillation detector is a valid option in realizing a portable spectrometric system for “in situ” measurements. Due to high activity of some target parts, measurements with acceptable count-rate values can be performed at high distance from the detector or by using a purposely realized Lead-walled collimator. The identification of some key radionuclides allows to evaluate the surface dose behaviour as function of decay time for each component. The largest activity values are related to radionuclides with half-life of 70-80 days, while radionuclides with higher half-lives represent less than 10 per cent of the total activity. For an Havar™ foil, the surface dose rate will be reduced to about 1/1000 of the starting value after a decay period of approximately 4 years (about 1500 days), with a relatively safety at product disposal work. For a longer time, only long-lived radionuclides 57Co, 60Co, and 54Mn contribute to activities of main target components.