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Evan Groopman (Fed)

Research Physicist

Evan joined the Surface and Trace Chemical Analysis Group at NIST as a research physicist in 2021. His scientific background is in correlated microanalysis of extraterrestrial and nuclear materials, particularly using secondary ion mass spectrometry (SIMS), and electron and X-ray microscopy. Evan earned his Ph. D. from Washington University in St. Louis in 2015 studying presolar stardust grains, connecting laboratory measurements of these microscopic particles to models of stellar nucleosynthesis. Between 2015 and 2021, Evan worked at the U.S. Naval Research Laboratory (NRL), as a National Research Council (NRC) postdoc and as a Fed, developing a unique combination mass spectrometer called the NAUTILUS by coupling a SIMS to a single-stage accelerator mass spectrometer (SSAMS). This combination minimized the molecular isobaric background in SIMS analysis of trace and high-mass elements in complex matrices. Evan designed and developed novel measurement paradigms, instrument control hardware and software, and data analysis programs for the NAUTILUS. These developments yielded exciting new science, such as the discovery of fissionogenic Cs sequestration in Ru-rich metallic aggregates (“epsilon particles”) in the Oklo natural nuclear reactor ore. Evan’s current research interests at NIST include applying SIMS and correlated techniques to nuclear materials and cosmochemistry challenges, and developing new instrumentation, methods, and software to address unmet analytical needs.


NRC Postdoc Opportunities

Secondary Ion Mass Spectrometry (SIMS)

Selected Publications

E. E. Groopman, L. R. Nittler, D. G. Willingham, A. M. Meshik, O. V. Pravdivtseva. “Long-Term Retention and Chemical Fractionation of Fissionogenic Cs and Tc in Oklo Natural Nuclear Reactor Fuel” (2021) Applied Geochemistry 131, 105047 doi: 10.1016/j.apgeochem.2021.105047

E. E. Groopman, D. G. Willingham, A. J. Fahey, K. S. Grabowski. “An overview of NRL's NAUTILUS: a combination SIMS-AMS for spatially resolved trace isotope analysis” (2020) Journal of Analytical Atomic Spectroscopy, 35, 600-625 doi: 10.1039/c9ja00344d

D. G. Willingham, E. E. Groopman, L. Sangely. “U-Pu Mixed Oxide Particle Analysis by NAUTILUS and Implications for Next Generation Verification Challenges” (2020) Journal of the American Society of Mass Spectrometry, 31 (8), 1647-1655 doi: 10.1021/jasms.0c00097

E. E. Groopman, D. G. Willingham, A. P. Meshik, O. V. Pravdivtseva. “Discovery of Fissionogenic Cs and Ba Capture Five Years after Oklo Reactor Shutdown” (2018) Proceedings of the National Academy of Sciences, 115 (35), 8676-8681 doi: 10.1073/pnas.1807267115

D. G. Willingham, E. E. Groopman, K. S. Grabowski, L. Sangely. “Direct, uncorrected, molecule-free analysis of 236U from uranium-bearing particles with NAUTILUS: a new kind of mass spectrometer” (2018) Analyst, 143, 5364 doi: 10.1039/c8an01451e

E. E. Groopman, K. S. Grabowski, A. J. Fahey, L. Kööp. “Rapid, Molecule-Free, in-situ Rare Earth Element Abundances by SIMS-SSAMS” (2017) Journal of Analytical Atomic Spectroscopy, 32, 2153-2163 doi: 10.1039/C7JA00294G

E. E. Groopman, L. R. Nittler. “Correlated XANES, TEM, and NanoSIMS of Presolar Graphite Grains” (2017) Geochimica et Cosmochimica Acta, 221, 219-236 doi: 10.1016/j.gca.2017.02.011

A. J. Fahey, E. E. Groopman, K. S. Grabowski, K. C. Fazel. “Measurement of Uranium Isotopes in Particles of U3O8 by Secondary Ion Mass Spectrometry-Single Stage Accelerator Mass Spectrometry (SIMS-SSAMS).” (2016) Analytical Chemistry 88 (14), 7145–7153 doi:10.1021/acs.analchem.6b01209

E. Groopman, E. Zinner, S. Amari, et al. “Inferred Initial 26Al/27Al Ratios in Presolar Stardust Grains from Supernovae are Higher than Previously Estimated.” (2015) The Astrophysical Journal, 809, 31 doi:10.1088/0004-637X/809/1/31

E. Groopman, L. R. Nittler, T. J. Bernatowicz, E. Zinner. “NanoSIMS, TEM, and XANES Studies of a Unique Presolar Graphite Grain.” (2014) The Astrophysical Journal, 790, 9 doi:10.1088/0004-637X/790/1/9

E. Groopman, T. Bernatowicz, E. Zinner. “C, N, and O isotopic heterogeneities in low-density supernova graphite grains from Orgueil.” (2012) The Astrophysical Journal Letters, 754, L8 doi:10.1088/2041-8205/754/1/L8


2019 -  Alan Berman Research Publication Award, Department of the Navy, for the best publication in the Materials Science and Technology Division, NRL, for “Discovery of Fissionogenic Cs and Ba Capture Five Years after Oklo Reactor Shutdown” PNAS, 115 (35), 8676-8681


Created October 26, 2021, Updated March 24, 2023