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 0.5-20 pm with proper concentration of uranium; the accuracy of locating particles is better than 5 pm; and the transference efficiencies of particles from swipes to Re filaments are similar to 90%, similar to 73% and similar to 43% for particle sizes 0.5-5, 5-10 and 10-20 mu m, respectively. Analysis of U-135 and U-138 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. (C) 2008 Elsevier Ltd. All rights reserved.