Fluoride target matrices for determination of ²³⁶U by accelerated mass spectrometry

At present, oxide matrices are most often used for the determination of ²³⁶U, in which uranium is usually incorporated in the crystal structure of iron oxide. Newly developed fluoride materials prove to be a suitable alternative, promising the possibility of achieving an order of magnitude higher sensitivity. As part of ongoing research in this area, the previously developed process for the preparation of fluoride target materials based on the reduction and co-precipitation of uranium from acidic solutions together with lanthanide fluorides acting as a non-isotopic carrier was further optimized. The analysis of samples by AMS MILEA in cooperation with ETH Zuerich proved the possibility of reproducible achievement of high ionic yields, with very promising results also performed one of the very first measurements of isotope ratios ²³⁶U/²³⁸U using fluoride matrices. (authors)