Direct Determination of Oxygen Isotope in Uranium Oxide by Thermal Ionization Mass Spectrometry

The thermal ionization mass spectrometry (TIMS) method for direct determination of the oxygen isotopic ratio in uranium oxide powders was established through eliminating the influence of oxygen in the environment, sample particle sizes, material of rhenium and tantalum filaments and measurement mode on results. The measurement parameters of mass spectrometer were optimized. The experimental results show that the relative deviation of TIMS method result and oxidation method result is 0.2%. The measuring precision of TIMS is better than 0.28%.