Preparation of a carrier free 124Sb tracer produced in the Sn (p, n) reaction

A carrier-free 124 Sb tracer was prepared for determining radioactive 125 Sb in highly contaminated and radioactive soil like one taken near the Fukushima Daiichi Nuclear Power Plant. The excitation function for the 124 Sb production was measured and compared to previous works to identify the optimum proton energy for the 124 Sn (p, n) reaction by a stack method. The maximum production of 124 Sb in the reaction was found at an incident proton beam energy of 8–9 MeV. Except for 124 Sb, the reaction produced short-lived by-products and practically no 125 Sb. Antimony was isolated from tin matrix by dissolving the irradiated target and extracting to isoamyl acetate. Then the carrier-free 124 Sb tracer solution was purified by passing it through an anion exchange resin column. The radioactivity of 124 Sb was recovered to more than 50% of the production, and provided successfully as a tracer solution free from tin due to the examined chemical procedure.