Take a sneak peek at the new NIST.gov and let us know what you think!
(Please note: some content may not be complete on the beta site.).

View the beta site
NIST logo

Publications Portal

You searched on: Author: Ryan Fitzgerald

Displaying records 1 to 10 of 28 records.
Resort by: Date / Title

1. Long-term stability of carrier-added Ge-68 standardized solutions
Published: 3/1/2016
Authors: Brian Edward Zimmerman, Denis E Bergeron, Ryan P Fitzgerald, Jeffrey T Cessna
Abstract: Tests for chemical stability were carried out on carrier-added 68Ge solutions prepared and calibrated in 2007 and 2011 to evaluate the suitability of the specific composition as a potential Standard Reference Material. Massic count rates of the store ...

2. Corrections for the Combined Effects of Decay and Dead Time in Live-Timed Counting of Short-Lived Radionuclides
Published: 12/5/2015
Author: Ryan P Fitzgerald
Abstract: Studies and calibrations of short-lived radionuclides, for example 15O, are of particular interest in nuclear medicine. Yet counting experiments on such species are vulnerable to an error due to the combined effect of decay and dead time. Separat ...

3. Monte Carlo based approach to the LS-NaI ß-¿ anticoincidence extrapolation and uncertainty
Published: 11/1/2015
Author: Ryan P Fitzgerald
Abstract: The β-γ anticoincidence method is used for the primary standardization of β-, β+, electron capture (EC), α, and mixed-mode radionuclides. Efficiency extrapolation using one or more γ ray coincidence gates is typically ...

4. Development of an Ultra-Pure, Carrier-Free 209Po Solution Standard
Series: Journal of Research (NIST JRES)
Published: 7/23/2015
Authors: Ronald Colle, Ryan P Fitzgerald, Lizbeth Laureano-Perez
Abstract: Ultra-pure, carrier-free 209Po solution standards have been prepared and standardized for their massic alpha-particle emission rate. The standards, which will be disseminated by the National Institute of Standards and Technology (NIST) as Standard Re ...

5. Uncertainties in 4-pi-beta-gamma coincidence counting
Published: 5/22/2015
Authors: Ryan P Fitzgerald, Claude Bailat, Christophe Bobin, John Keightley
Abstract: The 4-pi-beta-gamma coincidence counting method and its close relatives are widely used for the primary standardization of radioactivity. Both the general formalism and specific implementation of these methods have been well-documented. In partic ...

6. Uncertainty evaluation in activity measurements using ionization chambers
Published: 5/22/2015
Authors: Marie Noelle Amiot, V Chiste, Ryan P Fitzgerald, F Juget, Carine Michotte, Andrew Pearce, G Ratel
Abstract: Pressurized re-entrant (or 4π) pressurized ionization chambers (ICs) connected to current- measuring electronics are used for activity measurements of photon emitting radionuclides and some beta emitters in the field of metrology and nuclear ...

7. Uncertainty of nuclear counting
Published: 5/22/2015
Authors: Stefaan Pomme, John Keightley, Ryan P Fitzgerald
Abstract: Nuclear counting is affected by pulse pileup and system dead time which induce rate-related count loss and alter the statistical properties of the counting process. Fundamental equations are presented to predict deviations from Poisson statistics ...

8. Two determinations of the 223Ra half-life
Published: 5/1/2015
Authors: Denis E Bergeron, Ryan P Fitzgerald
Abstract: Ra-223 is an alpha-emitter that is being used as a bone-seeking radiotherapeutic agent. The relatively large uncertainty on its half-life (0.26 %, Bé et al., 2011) is an impediment to precision activity assays. We have performed two series of measure ...

9. Determination of photon emission probabilities for the main gamma-rays of 223Ra in equilibrium with its progeny
Published: 3/11/2015
Authors: Leticia S Pibida, Brian Edward Zimmerman, Ryan P Fitzgerald, Lynne Emily King, Jeffrey T Cessna, Denis E Bergeron
Abstract: The currently published 223Ra gamma-ray emission probabilities display a wide variation in the values depending on the source of the data. The National Institute of Standards and Technology performed activity measurements on a 223Ra solution that was ...

10. A review of NIST primary activity standards for 18F: 1982 to 2013
Series: Journal of Research (NIST JRES)
Published: 8/27/2014
Authors: Denis E Bergeron, Jeffrey T Cessna, Bert M Coursey, Ryan P Fitzgerald, Brian Edward Zimmerman
Abstract: The new NIST activity standardization for 18F differs from results obtained between 1998 and 2008 by 4 %. The new results are considered to be very reliable; they are based on a battery of robust primary measurement techniques and bring the NIST sta ...

Search NIST-wide:

(Search abstract and keywords)

Last Name:
First Name:

Special Publications:

Looking for a NIST Special Publication (NIST SP Series)? Place the series number and dash in the report number field (Example: 800-) and begin your search.

  • SP 250-XX: Calibration Services
  • SP 260-XX: Standard Reference Materials
  • SP 300-XX: Precision Measurement and Calibration
  • SP 400-XX: Semiconductor Measurement Technology
  • SP 480-XX: Law Enforcement Technology
  • SP 500-XX: Computer Systems Technology
  • SP 700-XX: Industrial Measurement Series
  • SP 800-XX: Computer Security Series
  • SP 823-XX: Integrated Services Digital Network Series