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Ryan P. Fitzgerald

Ryan Fitzgerald is a physicist working in the field of Ionizing Radiation, creating primary standards for radionuclides and researching new and improved methods for measuring radiation and quantifying radioactive material. Dr. Fitzgerald has published dozens of papers on nuclear physics, radiation detection, and primary standards for radioactivity. He has collaborated on radioactivity applications with others at NIST that have positive impact across numerous fields of science and society, including medicine, energy, safety, and security. One long-term interest is in developing computer simulations of radiation detection instruments to improve performance and decrease uncertainty in measurement. His latest interests are in applying new technologies to radiation physics, including developing cryogenic spectrometers for characterizing radioactive decay, and radiation sensors based on photonic resonators.

Projects & Collaborations

Publications

Primary standardization of Ra-224 activity by liquid scintillation counting

Author(s)
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

On-chip Silicon Photonics Radiation Sensors

Author(s)
Nikolai N. Klimov, Zeeshan Ahmed, Lonnie T. Cumberland, Ileana M. Pazos, Ronald E. Tosh, Ryan P. Fitzgerald
We have examined the impact of cobalt-60-ray radiation up to 1 megagray (MGy) absorbed dose on silicon photonic devices. We do not find any systematic impact

Preparation and calibration of a Protactinium-231 reference material

Author(s)
Richard M. Essex, Ross W. Williams, Kerri C. Treinen, Ronald Colle, Ryan P. Fitzgerald, Raphael Galea, John Keightley, Jerome J. LaRosa, Lizbeth Laureano-Perez, Svetlana Nour, Leticia S. Pibida
A 231Pa reference material has been characterized for amount of Pa. This reference material is primarily intended for calibration of 233Pa tracers produced for

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

Author(s)
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 May 21, 2019