Measurement of Uranium Isotopes in Particles of U₃O₈ by Secondary Ion Mass Spectrometry–Single-Stage Accelerator Mass Spectrometry (SIMS–SSAMS)

Abstract

A commercial secondary ion mass spectrometer (SIMS) was coupled to a ± 300 kV single-stage accelerator mass spectrometer (SSAMS). Positive secondary ions generated with the SIMS were injected into the SSAMS for analysis. This combined instrument was used to measure the uranium isotopic ratios in particles of three certified reference materials (CRM) of uranium, CRM U030a, CRM U500, and CRM U850. The ability to inject positive ions into the SSAMS is unique for AMS systems and allows for simple analysis of nearly the entire periodic table because most elements will readily produce positive ions. Isotopic ratios were measured on samples of a few picograms to nanograms of total U. Destruction of UH(+) ions in the stripper tube of the SSAMS reduced hydride levels by a factor of ∼3 × 10(4) giving the UH(+)/U(+) ratio at the SSAMS detector of ∼1.4 × 10(-8). These hydride ion levels would allow the measurement of (239)Pu at the 10 ppb level in the presence of U and the equivalent of ∼10(-10 236)U concentration in natural uranium. SIMS-SSAMS analysis of solid nuclear materials, such as these, with signals nearly free of molecular interferences, could have a significant future impact on the way some measurements are made for nuclear nonproliferation.

Discovery of fissionogenic Cs and Ba capture five years after Oklo reactor shutdown

“…We studied the spatial distribution and isotopic abundances of fission and neutron capture products in a sample from drill hole S2 in gallery SD.37 of Oklo RZ 13 (6-8) using the NAval Ultra Trace Isotope Laboratory's Universal Spectrometer (NAUTILUS) at the US Naval Research Laboratory (NRL). NAUTILUS is a combination secondary ion mass spectrometer (SIMS) and single-stage accelerator mass spectrometer (SSAMS), which enables the micrometer-scale and molecular-isobar-free analysis of samples in situ (14)(15)(16). NAUTILUS provides a state-of-the-art, direct, molecule-free isotope imaging capability over regions 10-500 μm in…”

Rapid paper spray mass spectrometry characterization of uranium and exemplar molecular species

“…energy‐dispersive X‐ray microanalysis), and mass spectrometry (e.g. multi‐collector inductively coupled plasma mass spectrometry (ICP‐MS) and ion mobility spectrometry) . A shortcoming of current analytical paradigms is the lack of chemical information provided by these analyses.…”

Progress and Application on the Analysis of Anthropogenic Radionuclide236U

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