Measuremets of presolar grain in meteorite using neutron activation analysis with multi-parameter coincidence method

Hatsukawa, Yuichi; Miyamoto, Yutaka; Hayakawa, Takehito; Toh, Yosuke; Kimura, Atsushi; Oshima, Masumi

Journal of Radioanalytical and Nuclear Chemistry, 276(1), p.213 - 216, 2008/04

https://doi.org/10.1007/s10967-007-0435-3

Method of multiparameter coincidence spectrometry based on - coincidence is widely used in the field of nuclear structure studies, and has produced many successful achievements. We developed a new technique of trace element analysis based on neutron activation analysis with coincident -ray detection. In order to improve the low efficiency of coincident -ray detection, an array of 16 Ge detectors with BGO Compton suppressors was used for this method. High sensitive trace element analyses without chemical separation were carried out by the combination of neutron activation analysis and the method of multiparameter coincidence spectroscopy. In the case of neutron activation analysis, measurements of -rays from trace elements are strongly interfered by the -rays from major elements, e.g., Na, Mn. So usually chemical separation processes are required to eliminate the major elements for determination of the trace elements. But using this method, we can detect very weak rays from trace elements without chemical separations. In this study, we try to measure trace elements in presolar grains. Presolar grains are synthesis in the Super nova or Red giant, and found in the primitive meteorite. We obtained presolar grains from the Allende meteorite, and try to measure trace elements in the grains using this method.