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Richard Essex (Fed)

Dr. Essex has been a physical scientist in the Radioactivity Group at the National Institute of Standards and Technology since 2015. His primary responsibility at NIST are developing environmental level measurements of radioactive nuclides by mass spectrometry. Dr. Essex has degrees in Geological Science from the University of Rhode Island, Virginia Tech, and Brown University. He held several positions as an environmental regulator prior to becoming a staff member at the DOE’s New Brunswick Laboratory (NBL). Dr. Essex was at NBL for 14 years where his work included production and characterization of reference materials for analysis of nuclear materials, developing test materials for nuclear forensics analysis, and coordination of a DHS-sponsored program for production of reference materials. As part of his ongoing activities at NIST, Dr. Essex is working to enhance measurement of radioactive nuclides by developing isotope ratio mass spectrometry capabilities for radioactive material and contributing to an ongoing True Bq IMS prjoect.


Gravimetric deposition of microliter drops with radiometric confirmation

Denis E. Bergeron, Richard Essex, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren, Ryan P. Fitzgerald
A manual gravimetric dispensing technique is demonstrated using a micropipettor modified for use with removeable microcapillaries. Liquid scintillation sources

Toward a New Primary Standardization of Radionuclide Massic Activity Using Microcalorimetry and Quantitative Milligram-Scale Samples

Ryan P. Fitzgerald, Bradley Alpert, Dan Becker, Denis E. Bergeron, Richard Essex, Kelsey Morgan, Svetlana Nour, Galen O'Neil, Dan Schmidt, Gordon A. Shaw, Daniel Swetz, R. Michael Verkouteren, Daikang Yan
We present a new paradigm for the primary standardization of radionuclide activity per mass of solution (Bq/g). Two key enabling capabilities are 4π decay

New reference materials for trace-levels of actinide elements in plutonium

Richard Essex, Lav Tandon, Amy Gaffney, Cole Hexel, Debbie Bostick, Lisa Colletti, Diana Decker, Casey Finstad, Joseph Giaquinito, Elmer Lujan, John Partridge, Benjamin Roach, John Rolinson, Kyle Samperton, Alice Slemmons, Khalil Spencer, Floyd Stanley, Lisa Townsend, Kerri Treinen, Ross Williams, Christopher Worley
Two plutonium oxides were prepared as unique reference materials for actinides occurring as trace constituents in Pu. Each reference material unit is
Created May 21, 2019, Updated December 8, 2022