KCS

A thermal ionization mass spectrometer (TIMS) equipped with a multiple collector system was utilized for the study on the measurement accuracy and precision based on the detection methods and the amounts of uranium. Various amounts of samples were loaded in the mass spectrometer followed by being measured with three different detection configurations, which were multi-dynamic, dynamic, and simultaneous static detection methods. Only static detection method enabled us to ensure reliable accuracy and precision for the isotopic measurement of the uranium with 1 pg, which corresponds to the amount of uranium contained in a typical single-particle collected from a nuclear facility. Examples for isotopic analysis of uranium single-particles performed by TIMS with fission-track (FT) or scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS) techniques were shown as applications of this study to nuclear safeguards and nuclear forensics. The excellent agreement of the measurement with the certified value showed our single-particle analysis based on FT-TIMS and SEM-TIMS measurements suitable for the analysis of unknown uranium particles with high precision and accuracy.