Progress in the Development of RIMS for Quantifying Actinide Isotope Ratios for Nuclear Forensics Applications

We report progress in developing resonance ionization mass spectrometry (RIMS) for quantifying isotope ratios in U and Pu for nuclear forensic applications. We highlight recent improvements in instrumentation and methodology that have led to increased precision and stability in the measured isotope ratios. We also report measurements of U isotope abundance on several working reference materials and the corresponding uncertainty analysis. Finally, we will discuss outstanding issues for the routine application of RIMS to materials of nuclear forensics interest.