Use of Scanning Electron Microscopy to Enhance the Accuracy of Mass Spectrometry Analysis of Uranium Microparticles

A sample containing microparticles of two different uranium materials with distinct uranium isotopic compositions was analyzed during an international experiment. Mass spectrometric analysis of 25 particles revealed that, within the measurement error, six particles had an isotopic composition consistent with that of the first material, and three particles were consistent with the second material. However, the uranium isotopic composition of the remaining 16 particles did not match either of the known materials. This indicates that the preliminary examination of uranium microparticles by scanning electron microscopy can identify particles carrying information about the isotopic composition of the source materials.