Study on analysis of isotopic ratio of uranium-bearing particle in swipe samples by FT-TIMS

A fission track (FT) technique has been developed for searching for, locating and transferring a single uranium-bearing particle from swipe samples. The technique consists of (1) searching for uranium-bearing particles in swipe samples by FT technique; (2) locating the particle by FT cluster under optical microscope and (3) transferring the particle from the swipe sample to a filament (Re) of TIMS. The study shows that the efficiency of searching for uranium-bearing particles reaches 90% for particles of size 0.5–20μm with proper concentration of uranium; the accuracy of locating particles is better than 5μm; and the transference efficiencies of particles from swipes to Re filaments are ∼90%∼90%, ∼73%∼73% and ∼43%∼43% for particle sizes 0.5–5, 5–10 and 10–20μm, respectively. Analysis of U235 and U238 isotopic abundances in the particles by TIMS shows that the isotopic abundances are in agreement with those of original reference materials. The study shows that the FT technique combined with TIMS is a feasible, easy-managing and accurate method for determination of uranium isotopes of a single microscopic particle.