Rapid separation of 110In from enriched Cd targets by thermal diffusion

110In (image) is a short-lived positron emitting indium isotope that can be produced in high radioactivity amounts by a low-energy accelerator and from an enriched 110Cd-target. We present a simple, non-destructive and rapid method to separate radioactive indium isotopes from cadmium targets with the special aim to produce 110In. The irradiated target foils were heated up to 306°C, that is close to the melting point of cadmium. At this temperature the indium isotopes were diffusing out to the surface of the foils. After the end of the heating a high concentration of indium radioactivity was found at the surface of the target. By dipping the foils into a weak acid more than 60% of the radioactivity was etched off the target with less than 2% loss of the target material.