High sensitive elemental analysis using Multiparameter Coincidence Spectrometer, GEMINI-II

Method of multi-parameter coincidence spectrometry based on coincidence is widely used in the field of nuclear structure studies, and has produced many successful achievements. High sensitive trace element analyses without chemical separation were carried out by the combination of neutron activation analysis and the method of multi-parameter coincidence spectroscopy. In the case of neutron activation analysis, measurements of γ-rays from trace elements are strongly interfered by the γ-rays from major elements, e.g., 24Na, 56Mn. So usually Chemical separation processes are required to eliminate the major elements for determination of the trace elements, In this study, using neutron activation analysis with multi-parameter coincidence spectrometry method which has been developed at JAERI, a non-destructive, high sensitive determination of trace elements has been realized. The multiple coincidence spectrometry measurements are performed with an array of 19 Ge detectors, named GEMINI-II. About 10 ppt of iridium in geological samples can be determined using this system without chemical separations. In this paper, the latest results of analyses of geological and meteorite samples will be discussed.