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Search Publications by: Denis E. Bergeron (Fed)

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Displaying 76 - 100 of 139

Two determinations of the Ge-68 half-life

October 19, 2017
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Brian E. Zimmerman
In nuclear medicine, 68Ge is used to generate 68Ga for imaging by positron emission tomography (PET) and sealed sources containing 68Ge/68Ga in equilibrium have been adopted as long-lived calibration surrogates for the more common PET nuclide, 18F. We

Monte Carlo modelling of live-timed anticoincidence (LTAC) counting for Cu-64

September 20, 2017
Author(s)
Denis E. Bergeron, Ryan P. Fitzgerald
The radionuclide copper-64 is a promising candidate for nuclear medicine, but its complex decay creates challenges in the primary standardization of its activity. Monte Carlo simulations of live timed anticoincidence (LTAC) counting of 64Cu were used to

Phase stability and lithium loading capacity in a liquid scintillation cocktail

August 2, 2017
Author(s)
Denis E. Bergeron, Mark A. Tyra, Hans P. Mumm
Liquid scintillation cocktails loaded with neutron capture agents such as 6Li are used in both neutron and neutrino detectors. For detectors designed to operate over extended timespans, long-term stability can be a concern. We demonstrate the

Evidence against solar influence on nuclear decay constants

August 24, 2016
Author(s)
Denis E. Bergeron, Ryan P. Fitzgerald, Leticia S. Pibida, Stefaan Pomme
The exponential decay of radionuclides as a function of time is a cornerstone of nuclear physics and radionuclide metrology. Decay constants for spontaneous radioactive decay are considered invariable in time and space. This convenient trait allows

Micellar phase boundaries under the influence of ethyl alcohol

May 16, 2016
Author(s)
Denis E. Bergeron
The Compton spectrum quenching technique is used to monitor the effect of ethyl alcohol (EtOH) additions on phase boundaries in two systems. In toluenic solutions of the nonionic surfactant, Triton X-100, EtOH shifts the boundary separating the first clear

Comparison of C-14 liquid scintillation counting at NIST and NRC Canada

March 1, 2016
Author(s)
Denis E. Bergeron, Raphael Galea, Lizbeth Laureano-Perez, Brian E. Zimmerman
An informal bilateral comparison of 14C liquid scintillation (LS) counting at the National Research Council of Canada (NRC) and the National Institute of Standards and Technology (NIST) has been completed. Two solutions, one containing 14C-labeled sodium

Long-term stability of carrier-added Ge-68 standardized solutions

March 1, 2016
Author(s)
Brian E. Zimmerman, Denis E. Bergeron, Ryan P. Fitzgerald, Jeffrey T. Cessna
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 stored

Revision of the NIST Standard for 223Ra: New Measurements and Review of 2008 Data

July 1, 2015
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Leticia S. Pibida
After discovering a discrepancy in the transfer standard currently being disseminated by the National Institute of Standards and Technology (NIST), we have performed a new primary standardization of the alpha-emitter 223Ra using Live-timed Anticoincidence