Isotopic spectroscopy of uranium atomic beams produced by thermal reduction of uranium compounds

Highlights: • Atomic beams of neutral uranium are generated using uranium compounds as starting material. • Reducing agent lutetium metal is added to micro-crucibles containing uranium samples. • High-resolution laser absorption spectroscopy through the atomic beam is conducted. -- Abstract: We present a method for producing atomic beams of uranium from molecular uranium precursors in a micro-crucible. In previous work, we have shown that uranium in an atomic beam can be analyzed for isotopic abundances down to enrichment levels of 0.7%. Here, we show that the same method can be utilized to analyze samples of any of the most common uranium-containing compounds to obtain the same quality of analytical results. This technique relies only on the addition of a metal species capable of reducing the uranium compound of interest. This work presents a brief discussion of the necessary criteria for thermal reduction, development and proof-of-principle of the technique using Er₂O₃ as a non-radioactive surrogate material, and application to samples of the uranium compounds UO₂, U₃O₈, UO₂(NO₃)₂, UO₂F₂, and UF₄, to obtain isotope-resolved absorption spectra from an atomic beam produced from these molecular precursors.