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Brian E. Zimmerman (Fed)

Dr. Brian Zimmerman is currently the Leader of the Radioactivity Group at the National Institute of Standards and Technology. The Group is responsible for the dissemination of the Systèm International (SI) unit of radioactivity, the becquerel. The standards developed in the Radioactivity Group have applicability in widely diverse fields such as nuclear medicine, nuclear security, environmental monitoring, fundamental physics research, and nuclear power.

Dr. Zimmerman received his PhD in Nuclear Chemistry from the University of Maryland, College Park and continued his work in the field of nuclear structure physics and nuclear spectroscopy, particularly proton radioactivity, as a postdoc at the University of Tennessee (Knoxville). He joined the Radioactivity Group at NIST in 1995 as a Research Chemist to lead the team responsible for developing national standards of radioactivity related to medical applications. During his time at NIST, this program has developed radioactivity standards for over 20 unique radionuclides that are used in therapeutic and diagnostic nuclear medicine. These standards help ensure accurate measurements of administered activity, leading to safer and more effective use of radiopharmaceuticals. He was awarded a NIST Bronze Medal in 2002 for his leadership of NIST programs in Health Care. In more recent years, the program has focused on the development of standards for Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPECT) and published the first calibration methodology that enables direct traceability for quantifying the amount of radioactivity in solid PET and SPECT phantoms. Dr. Zimmerman and his team won the 2016 William P. Slichter Award for applying this method to provide traceable calibrations for commercial PET phantoms. 

Between 2003 and 2006, Dr. Zimmerman worked at the International Atomic Energy Agency (IAEA) in Vienna, Austria, where he was responsible for establishing training programs in radioactivity measurement and imaging physics in developing countries, particularly in Africa and Eastern Europe. While at the IAEA, he initiated several new projects that ultimately resulted in the production of three documents aimed at Quality Control in nuclear medicine that are widely used in the IAEA Member States: Quality Assurance for Radioactivity Measurement in Nuclear Medicine (IAEA Technical Report Series No. 454), Quality Assurance for PET and PET/CT Systems (IAEA Human Health Series No. 1), and Quality Assurance for SPECT Systems (IAEA Human Health Series No. 6). He was a staff member of the IAEA when it was awarded the Nobel Prize for Peace in 2005. 

Dr. Zimmerman currently serves as President of the International Committee on Radionuclide Metrology and is Chair of the BIPM Radionuclide Therapy and Quantitative Imaging Working Group. He served as Editor-in-Chief of the journal Applied Radiation and Isotopes from 2004 to 2020 and currently serves as Consulting Editor for the journal.

His current research includes radionuclide metrology, nuclear data evaluation (as a member of the Decay Data Evaluation Project, DDEP), Monte Carlo applications in radionuclide metrology and medical physics, internal dosimetry, and medical imaging physics and he has more than 100 peer-reviewed publications.


Primary standardization of 212Pb activity by liquid scintillation counting

Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Lizbeth Laureano-Perez, Leticia Pibida, Brian E. Zimmerman
An activity standard for 212Pb in equilibrium with its progeny was realized, based on triple-to-double coincidence ratio (TDCR) liquid scintillation (LS)

Calorimetry in Computed Tomography Beams

Heather H. Chen-Mayer, Ronald Tosh, Fred B. Bateman, Paul Bergstrom, Brian E. Zimmerman
A portable calorimeter for direct realization of absorbed dose in medical computed tomography (CT) procedures was constructed and tested in a positron emission

Primary standardization of Ra-224 activity by liquid scintillation counting

Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Brian E. Zimmerman, Lizbeth Laureano-Perez, Ronald Colle, Leticia S. Pibida, Elisa Napoli
A standard for 224Ra activity has been developed, based on triple-to-double coincidence ratio (TDCR) liquid scintillation (LS) counting. The standard was

Standardization of I-124 by three liquid scintillation-based methods

Denis E. Bergeron, Leticia S. Pibida, Brian E. Zimmerman, Jeffrey T. Cessna, Ryan P. Fitzgerald
A solution of 124I was standardized for activity by 4πβ(LS)-γ(NaI) live-timed anticoincidence (LTAC) counting, with confirmatory measurements by triple-to
Created July 30, 2019, Updated December 8, 2022