I came to LLNL as a post-doc in 2004 and fell in love with the culture, unmatched passion of the staff, and cutting-edge science of the lab.  Throughout my career I have been involved in a wide range of scientific and mission driven projects including nuclear forensics, materials science, oceanography, nuclear physics, and radiochemistry.  In my current role as Director of the Center for Accelerator Mass Spectrometry, I enjoy the opportunity to lead a high impact scientific user facility and to mentor the next generation of lab scientists.

Graduate certificate in National Security Affairs, Texas A&M University, 2010

Ph.D. Nuclear Chemistry, University of Maryland, 2004

B.S. Chemistry, University of Kentucky, 1998

J.R. Jeffries, P.C. Myint, J.S. Smith, M.A. Wall, B. Baer, C.J. Wu, S.J. Tumey, “Influence of helium bubbles on the bulk equation of state of gold under static compression,” J. Vac. Sci & Tech A 43 (2025) 033205-1.

J.T. Wilkinson, S.J. Tumey, K.J. Moody, T.A. Brown, N. Gharibyan, “Proton- and deuteron-induced cross sections on natural platium,” Appl. Rad. Isot. 217 (2025) 111618.

A. Prasitthipayong, D.M Frazer, R. Zhang, H.T. Vo, S.J. Tumey, A.M. Minor, P. Hosemann, “Sample size effect phenomenon in microcompression testing of unirradiated and ion-irradiated 800H steel at high temperatures,” Mater. Charact. 215 (2024) 114046.

J.J. Goodell, J.A. Church, C.C. Keith, N.K. Harward, B. Pierson, S. Tumey, C. Dorais, B.B. Bandong, “Determining the ⁹Be(n,γ)¹⁰Be integral cross section at fission neutron energies,” Phys. Rev. C 109 (2024) 014625.

A. Kamboj, N. Almirall, T. Yamamoto, S. Tumey, E.A. Marquis, R. Odette, “Dose and dose rate dependence of precipitation in a series of surveillance RPV steels under ion and neutron irradiation,” J. Nucl. Mater. 588 (2024) 154772.

H.T. Vo, S. Pal, N. Almirall, S. Tumey, R. Odette, S.A. Maloy, “Dose and dose rate effects on the microstructural and mechanical stability of long-range ordered precipitates in Inconel 718,” Mater. Sci. Eng., A. 870 (2023) 144916.

J.A. Hammons, S.J. Tumey, S. Aubry, R.E. Rudd, Y. Idell, N. Bertin, J. Ilavsky, I. Kuzmenko, J.R. Jeffries, H.E. Lorenzana, “Processes controlling helium bubble dynamics at varying temperatures in simulated radioactive materials,” Materialia 25 (2022) 101529.

T.S. Anderson, A.J. Hidy, J.W. Boyce, F.M. McCubbin, S. Tumey, J.M. Dudley, N.C. Haney, G. Bardoux, M. Bonifacie, “Development towards stable chlorine isotope measurements of astromaterials using the modified Middleton source of an accelerator mass spectrometer,” Int. J. Mass. Spec. 477 (2022) 116849.

J.A. Hammons, S.J. Tumey, Y. Idell, J.R. Jeffries, “He Bubble Concentration, Size and Strain in Implanted Aluminum by SAXS/WAXS,” J. Mater. 72 (2020) 176-186.

K.J. Moody, N. Gharibyan, P.M. Grant, D.A. Shaughnessy, J.D. Despotopulos, S.J. Tumey, T.A. Brown, “Decay of Co-58(m),” Phys. Rev. C 99 (2019) 034307.

For a full list, see: Google Scholar

• Director’s Science and Technology Award for the Unprecedented Plutonium Data from NIF Experiments, LLNL, 2024
• Stand-out award, “Development and presentation of CAMS 2.0 strategic plan”, LLNL/AEED, 2021
• Excellence in Publication Award for Modern Methods for Characterization of historic core samples, LLNL/DDS&T, 2020
• Stand-out award, “Leadership in restarting CAMS operations after minimum safe operations”, LLNL/AEED, 2020
• Certificate of appreciation award, US DOE Office of Technical Nuclear Forensics, 2008
• Most outstanding poster award, LLNL Post-doc poster Symposium, 2005