An overview of NRL's NAUTILUS: a combination SIMS-AMS for spatially resolved trace isotope analysis

EE Groopman, DG Willingham, AJ Fahey… - Journal of analytical …, 2020 - pubs.rsc.org
We present a description of the capabilities and performance of the NAval Ultra-Trace
Isotope Laboratory's Universal Spectrometer (NAUTILUS) at the US Naval Research …

Improved uranium particle analysis by SIMS using O 3− primary ions

EE Groopman, TL Williamson… - Journal of analytical atomic …, 2022 - pubs.rsc.org
We have investigated the use of negative molecular oxygen primary ion beams (ie, O2− and
O3−) to determine the benefits of using such beams for uranium particle SIMS analyses …

Actinide elemental ratios of spent nuclear fuel samples by resonance ionization mass spectrometry

M Raiwa, MR Savina, AG Roberts… - Journal of the …, 2024 - ACS Publications
While resonance ionization mass spectrometry (RIMS) has demonstrated utility in measuring
isotopic compositions of elements in complex matrices without the need for chemical …

Spatially Resolved Characterisation of Low Mass Fraction Uranium Glass Working Reference Materials

D Willingham, J Wimpenny, E Groopman… - Geostandards and …, 2023 - Wiley Online Library
We present the results of a study to generate reference glasses that reflect an environment
analogous to historic nuclear fallout samples of interest for post‐detonation nuclear …

U–Pu Mixed Oxide Particle Analysis by NAUTILUS and Implications for Next-Generation Verification Challenges

D Willingham, E Groopman… - Journal of the American …, 2020 - ACS Publications
Precise and accurate measurement of U and Pu isotopes from micrometer-sized particles
represents new verification challenges for the International Atomic Energy Agency. The U …

Positive ion SIMS-SSAMS for trace analysis of materials

KS Grabowski, EE Groopman, BY Rock… - Nuclear Instruments and …, 2019 - Elsevier
By using a single-stage accelerator mass spectrometer (SSAMS) as a detector for a
secondary ion mass spectrometry (SIMS) instrument, spatially resolved trace analysis of …

Trace Element Concentrations in Microbial Fossils as a Novel Biosignature for Life on Ancient Earth and Beyond

A Gangidine - 2020 - search.proquest.com
The search for ancient life on Earth is complicated and often controversial due to the fossil
record consisting of microbial fossils (microfossils) which are simple in morphology and …

Rapid, Ultra-Sensitive Assessment of Elemental and Isotopic Compositions of Materials in Extreme Radiation Environments

E Groopman, D Willingham, S Jackson, A Gangidine… - 2020 - apps.dtic.mil
This report presents research conducted by the US Naval Research Laboratory (NRL) to
investigate material properties responsible for extending the lifetimes of nuclear reactor …