Skip to main content
U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

A New NIST Primary Standardization of 18F



Ryan P. Fitzgerald, Brian E. Zimmerman, Denis E. Bergeron, Jeffrey T. Cessna, Leticia S. Pibida, Denise S. Moreira


A new primary standardization of 18F by NIST is reported. The standard is based on live-timed beta- gamma anticoincidence counting with confirmatory measurements by three other methods: (i) liquid scintillation (LS) counting using CIEMAT/NIST 3H efficiency tracing; (ii) triple-to-double coincidence ratio (TDCR) counting; and (iii) NaI integral counting and HPGe γ-ray spectrometry. The results are reported as calibration factors for NIST-maintained ionization chambers (including some “dose calibrators”). The LS-based methods reveal evidence for cocktail instability for one LS cocktail. Using an ionization chamber to link this work with previous NIST results, the new value differs from the previous reports by about 4 %, but appears to be in good agreement with the Key Comparison Reference Value (KCRV) of 2005.
Applied Radiation and Isotopes


fluorine-18, 18F, F-18, primary standardization, anticoincidence, TDCR, CIEMAT/NIST, ionization chamber, dose calibrator
Created February 1, 2014, Updated November 10, 2018