SIMS analysis of Kr implanted UO2

A UO2 single crystal implanted with 83Kr was analysed with a shielded Cameca IMS 6f SIMS. The main objective was to develop measurement and quantification procedures for krypton in irradiated nuclear fuel. It was found that good quality 83Kr+ depth profiles could be obtained with a 16O2+ primary ion beam, a positive offset voltage of around 20 V and an oxygen leak. To convert erosion time to depth the craters produced during depth profiling were measured using an interferometer microscope. The measured depth profiles were in good agreement with the Gaussian implantation profiles. The 83Kr+ signal intensity, I, increased with current density, J, in accordance with the relationship I = A'J2 + B'J which indicates that ionisation occurred above the sample surface by inelastic collisions with oxygen atoms.