Determination of Uranium Isotope Ratio in Single Particle by Scanning Electron Microscope-Thermal Ionization Mass Spectrometer

The isotope analysis of single uranium-bearing particle is one of the most important techniques in environmental monitoring of nuclear safeguards. As a reliable and routine technique, the fission track-thermal ionization mass spectrometer (FT-TIMS) is complex and time-consuming. The scanning electron microscope-thermal ionization mass spectrometer (SEM-TIMS) is more efficient because the uranium-bearing particles are searched by SEM equipped with an energy dispersive X-ray (EDX) detector and transferred by micromanipulation which could simplify the procedure and save time. In this paper, the SEM-TIMS was introduced and monodisperse uranium oxide particles of known isotopic composition were measured by this approach. The result shows a good agreement with certified values.