Background

Tashi Parsons-Davis is a staff scientist at Lawrence Livermore National Laboratory with experience and interests in diverse aspects of nuclear and radiochemistry, materials chemistry, electrochemistry, analytical chemistry, and nuclear decay spectrometry.

As an undergraduate student Tashi did a summer research internship at Pacific Northwest National Laboratory where she worked on electrorefining high-purity copper for rare-event physics experiments, and also participated as a student in the American Chemical Society Nuclear and Radiochemistry Summer School at Brookhaven National Laboratory in the summer of 2006. She began working with Professor Heino Nitsche in January 2007 as a Junior Research Specialist at Lawrence Berkeley National Laboratory, where she participated in super-heavy element homologue chemistry experiments at the 88-inch cyclotron and helped develop new methods for preparation of nuclear reaction targets. Tashi started as a graduate student in the UC Berkeley Chemistry Department in the fall of 2007. She taught General Chemistry and the Radiochemistry Laboratory course at UC Berkeley as a graduate student instructor and continued her actinide chemistry research in the heavy element nuclear and radiochemistry group under Professor Nitsche. Her dissertation research focused on sorption, redox, and complexation interactions of aqueous plutonium and other f-elements with porous solid materials. Tashi’s research activities included synthesis and characterization of minerals, functionalized mesoporous silica, and mesoporous carbon materials, batch sorption experiments, and spectrometric characterization of plutonium at the liquid-solid interface.

Tashi joined LLNL in November 2014 as a postdoctoral researcher in the Chemical & Isotopic Signatures group, where she applied gamma spectrometry, alpha spectrometry, and other radiometric measurements to pre-detonation nuclear forensics and to research based on historic nuclear debris characterization. She continued studies of fundamental aqueous plutonium chemistry and has ongoing research interests in actinide chemistry and the environmental transport and behavior of radionuclides. Tashi developed skills and interest in radionuclide metrology as a postdoc through her efforts to verify high-precision decay constants for uranium isotopes. After transitioning to a staff scientist position at LLNL in 2017, Tashi continued to lead and contribute to multiple projects related to nuclear forensics, safeguards, international engagement, and preparation of standards and analytical reference materials in support of these technical applications. Much of her recent work focuses on post-detonation nuclear forensics, including development of additive manufacturing techniques for fabricating realistic test samples, and research into approaches and methods that could improve analytical timelines in nuclear forensics.

Ph.D., Chemistry, University of California, Berkeley, 2014

B.S., Chemistry, Mills College, 2006

Anna G. Servis., Tashi Parsons-Davis, Kenton J. Moody, Narek Gharibyan, Transport Modeling of Kinetically Limited Microscale Extraction Systems: Droplet and Supported Liquid Membrane Separations, Industrial & Engineering Chemistry Research. 60, 17, 6344-6354. DOI: 10.1021/acs.iecr.1c00740 (2021)

Anna G. Servis., Tashi Parsons-Davis, Kenton J. Moody, Narek Gharibyan, A 3D Printed Microfluidic Supported Liquid Membrane Module for Radionuclide Separations, Industrial & Engineering Chemistry Research. 60, 1, 629–638 (2021)

Essex RM, Williams RW, Rogers KT, Hexel CR, Parsons-Davis T, Treinen KC. A new highly enriched 233U reference material for improved simultaneous determination of uranium amount and isotope amount ratios in trace level samples. Talanta. 221:121638. DOI: 10.1016/j.talanta.2020.121638 (2021)

Jovanovic, Slobodan V., et al., Uncovering uranium isotopic heterogeneity of fuel pellets from the fifth collaborative materials exercise of The Nuclear Forensics International Technical Working Group. Journal of Radioanalytical and Nuclear Chemistry, Vol. 326, 3, pp. 1853-1866. https://doi.org/10.1007/s10967-020-07470-5 (2020)

Corliss K. Sio, Tashi Parsons-Davis, Elaine Lee, Josh Wimpenny, Andrew J. Pascall, Joshua D. Kuntz, John J. Goodell, Kevin E. Roberts, Bryan B. Bandong, Neil R. Bennett, Additive manufacturing of platinum group element (PGE) standard reference materials with a silica matrix. Rapid Communications in Mass Spectrometry, vol. 34, e8627 (2020)

Kattathu Mathew, et al., Inter-comparison of the Radio-chronometric Ages of Plutonium Certified Reference Materials with Distinct Isotopic Compositions. Analytical Chemistry, vol. 91, pp 11643-11652, https://pubs.acs.org/doi/10.1021/acs.analchem.9b02156 (2019)

Tashi Parsons-Davis, Josh Wimpenny, C. Brenhin Keller, Keenan Thomas, Kyle M. Samperton, Paul R. Renne, Roland Mundil, Ken Moody, Kim Knight, Michael J. Kristo, Ross Williams, New Measurement of the 238U Decay Constant with Inductively Coupled Plasma Mass Spectrometry, Journal of Radioanalytical and Nuclear Chemistry, Vol. 318, pp 711–721, https://doi.org/10.1007/s10967-018-6148-y (2018)

Amy M. Gaffney, Josh B.N. Wimpenny, Tashi Parsons-Davis, Ross W. Williams, Richard, A. Torres, Brandon, W. Chung, A Case Study in Plutonium Radiochronometry Using Multiple Isotope Systems, Journal of Radioanalytical and Nuclear Chemistry, Vol. 318, pp 287–295, https://doi.org/10.1007/s10967-018-6131-7 (2018)

Tashi Parsons-Davis, Kim Knight, Marc Fitzgerald, Gary Stone, Lee Caldeira, Christina Ramon, Michael Kristo, Application of Modern Autoradiography to Nuclear Forensic Analysis, Forensic Science International, Vol. 286, pp 223-232, https://doi.org/10.1016/j.forsciint.2018.03.027 (2018)

L. Lakosi, J. Zsigrai, A. Kocsonya, T.C. Nguyen, H. Ramebäck, T. Parsons-Moss, N. Gharibyan, K. Moody, Gamma Spectrometry in the ITWG CMX-4 Exercise, Journal of Radioanalytical and Nuclear Chemistry, Vol. 315, pp 409–416, https://doi.org/10.1007/s10967-017-5667-2 (2018)

Tashi Parsons-Moss, Stephen Jones, Jinxiu Wang, Eva Uribe, Dongyuan Zhao, and Heino Nitsche, Reduction of plutonium in acidic solutions by mesoporous carbons, Journal of Radioanalytical and Nuclear Chemistry, Vol. 307, Issue 3, pp 2593-2601, https://doi.org/10.1007/s10967-015-4647-7 (2016)

Tashi Parsons-Moss, Jinxiu Wang, Stephen Jones, Erin May, Daniel Olive, Zurong Dai, Mavrik Zavarin, Annie B. Kersting, Dongyuan Zhao, and Heino Nitsche, Sorption Interactions of Plutonium and Europium with Ordered Mesoporous Carbon, Journal of Materials Chemistry A, Vol. 2, DOI 10.1039/C4TA01740D, (2014)

Tashi Parsons-Moss, Harun Tüysüz, Deborah Wang, Stephen Jones, Daniel Olive, and Heino Nitsche, Plutonium Sorption to Nanocast Mesoporous Carbon, Radiochimica Acta, Vol. 102, Issue 4, DOI 10.1515/ract-2014-2138, (2014)

Mazhar N. Ali, Mitch A. Garcia, Tashi Parsons-Moss, and Heino Nitsche, Polymer-Assisted Deposition of Homogeneous Metal Oxide Films to Produce Nuclear Targets, Nature Protocols, Vol. 5, Issue 8, pages 1440-1446, DOI 10.1038/nprot.2010.105, (2010)

Garcia MA, Ali MN, Chang NN, Parsons-Moss T, Ashby PD, Gates JM, Stavsetra L, Gregorich KE, Nitsche H. Metal oxide targets produced by the polymer-assisted deposition method Nuclear Instruments and
Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 613: 396-400. DOI: 10.1016/j.nima.2009.09.084 (2010)

Gates JM, Stavsetra L, Sudowe R, Ali MN, Calvert MG, Dragojević I, Dvorak J, Dvorakova Z, Ellison PA, Garcia MA, Gregorich KE, Nelson SL, Parsons-Moss T, Nitsche H. Extraction of niobium and tantalum isotopes using organophosphorus compounds. Part II - Extraction of "carrier-free" concentrations from HCl/LiCl solutions Radiochimica Acta. 97: 173-176. DOI: 10.1524/ract.2009.1584 (2009)

Gates JM, Sudowe R, Stavsetra L, Ali M, Calvert MG, Dragojević I, Ellison PA, Garcia MA, Gharibyan N, Gregorich KE, Nelson SL, Neumann SH, Parsons-Moss T, Nitsche H. (2009) "Extraction of niobium and tantalum isotopes using organophosphorus compounds – Part I – Extraction of 'carrier-free' metal concentrations from HCl solutions" Radiochim Acta 97:167-172. DOI: 10.1524/ract.2009.1583 (2009)

Mitch A. Garcia, Mazhar N. Ali, Tashi Parsons-Moss, Paul D. Ashby, and Heino Nitsche, Metal Oxide Films Produced by Polymer-Assisted Deposition (PAD) for Nuclear Science Applications, Thin Solid Films, Vol. 516, Issue 18, pages 6261-6265, DOI 10.1016/j.tsf.2007.11.127, (2008)

Garcia MA, Ali MN, Chang NN, Parsons-Moss T, Ashby PD, Gates JM, Stavsetra L, Gregorich KE, Nitsche H. Heavy-ion irradiation of thulium(III) oxide targets prepared by polymer-assisted deposition. Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 592: 483-485. DOI: 10.1016/j.nima.2008.04.077 (2008)