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Search Publications by: Denis E. Bergeron (Fed)

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Displaying 1 - 25 of 71

Activity standard and calibrations for 227Th with ingrowing progeny

April 20, 2024
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Brittany Broder, Leticia Pibida, Ryan P. Fitzgerald, Morgan DiGiorgio, Elisa Napoli, Brian E. Zimmerman
Thorium-227 was separated from its progeny and standardized for activity by the triple-to-double coincidence ratio (TDCR) method of liquid scintillation counting. Confirmatory liquid scintillation-based measurements were made using efficiency tracing with

Ambient humidity, the overlooked influencer of radioactivity measurements

November 27, 2023
Author(s)
Stefaan Pomme, Michael P. Unterweger, Ryan P. Fitzgerald, Denis E. Bergeron, Leticia Pibida, International Collaboration
When verifying the validity of the exponential-decay law through 128 precise decay rate measurement series at various nuclear laboratories, minor violations have been observed in the shape of annual cycles in the residuals with different amplitudes and

Liquid scintillation efficiencies, gamma-ray emission intensities, and half-life for Gd-153

November 9, 2023
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Gulakhshan Hamad, Lizbeth Laureano-Perez, Leticia Pibida, Brian E. Zimmerman
Gadolinium-153 was standardized for activity by live-timed anticoincidence counting and an ampoule was submitted to the international reference system (SIR). Absolute emission intensities for the main γ rays were determined with calibrated high-purity

Gravimetric deposition of microliter drops with radiometric confirmation

September 9, 2023
Author(s)
Denis E. Bergeron, Richard Essex, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren, Ryan P. Fitzgerald
A manual gravimetric dispensing technique is demonstrated using a micropipettor modified for use with removeable microcapillaries. Liquid scintillation sources were prepared from a well-characterized 241Am reference solution, providing a radiometric check

Update of the BIPM comparison BIPM.RI(II)-K1.Co-60 of activity measurements of the radionuclide 60Co to include the 2020 result of the PTB (Germany), the 2020 result of the NIST (United States), the 2020 result of the SMU (Slovakia), the 2021 result of th

March 20, 2023
Author(s)
R Coulon, C Michotte, S Courte, M Nonis, F van Wyngaardt, M Smith, A Bowan, C Keevers, E Clark, M Zarifi, A Ravindra, DB Kulkarni, R Sharma, Marco Capogni, P De Felice, M Capone, P Carconi, A Fazio, C Bobin, R Lins da Silva, A Leiras, J de Almeida Rangel, M Aguiar Leobino da Silva, A Iwahara, Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Lizbeth Laureano-Perez, Leticia Pibida, MW Van Rooy, Jf Lubbe, MJ van Staden, John Keightley, A Pearce, N Ramirez, E Bendall, S Collins, T Ziemek, E Lech, P Saganowski, M Czudek, A Listkowska, O Nahle, Karsten Kossert, M Takacs, M Krivosik, I Bonkova
Since 1976, 30 laboratories have submitted 85 samples of 60Co to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identi_er BIPM.RI(II)-K1.Co-60. Recently, the PTB

Isotope Dilution Mass Spectrometry as an Independent Assessment for Mass Measurements of Milligram Quantities of Aqueous Solution

January 1, 2023
Author(s)
Richard Essex, Jacqueline L. Mann, Denis E. Bergeron, Ryan P. Fitzgerald, Svetlana Nour, Gordon A. Shaw, R. Michael Verkouteren
Isotope dilution mass spectrometry was used to independently assess the accuracy of mass measurement methods developed to quantitatively dispense milligram quantities of aqueous solution. Solutions of isotopically enriched 158Gd and enriched 155Gd were

Primary standardization of 212Pb activity by liquid scintillation counting

September 22, 2022
Author(s)
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) counting. A Monte Carlo-based approach to estimating uncertainties due to nuclear decay data

Toward a New Primary Standardization of Radionuclide Massic Activity Using Microcalorimetry and Quantitative Milligram-Scale Samples

February 24, 2022
Author(s)
Ryan P. Fitzgerald, Bradley Alpert, Dan Becker, Denis E. Bergeron, Richard Essex, Kelsey Morgan, Svetlana Nour, Galen O'Neil, Dan Schmidt, Gordon A. Shaw, Daniel Swetz, R. Michael Verkouteren, Daikang Yan
We present a new paradigm for the primary standardization of radionuclide activity per mass of solution (Bq/g). Two key enabling capabilities are 4π decay-energy spectrometry using chip-scale sub-Kelvin microcalorimeters and direct realization of mass by

Joint Determination of Reactor Antineutrino Spectra from 235U and 239Pu Fission using the Daya Bay and PROSPECT Experiments

February 22, 2022
Author(s)
Hans Pieter Mumm, Denis E. Bergeron, Mark Tyra, Svetlana Nour, Jerome LaRosa, The PROSPECT Collaboration
A joint determination of the reactor antineutrino spectra resulting from the fission of 235U and 239Pu has been carried out by the Daya Bay and PROSPECT collaborations. This letter defines the level of compatibility of 235U spectrum measurements from the

Joint Measurement of the 235U Antineutrino Spectrum with PROSPECT and STEREO

February 22, 2022
Author(s)
Hans Pieter Mumm, Denis E. Bergeron, Mark Tyra, Jerome LaRosa, Svetlana Nour, PROSPECT collaboration, STEREO collaboration
The PROSPECT and STEREO collaborations present a combined measurement of the pure 235U antineutrino spectrum, with site specific corrections and effects dependent on the separate detectors removed. The spectral measurements of the two highest-precision

BIPM comparison BIPM.RI(II)-K1.Gd-153 of activity measurements of the radionuclide 153Gd to include the 2020 result of the NIST (United States)

November 25, 2021
Author(s)
Denis E. Bergeron, Jeffrey T. Cessna, Ryan P. Fitzgerald, Lizbeth Laureano-Perez, Leticia Pibida, Carine Michotte, S Courte, M Nonis, R Coulon, S Judge
Since 1988, 3 laboratories have submitted 5 samples of 153Gd to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Gd-153. Recently, the NIST

MICROMETROLOGY IN PURSUIT OF QUANTUM RADIATION STANDARDS

November 9, 2021
Author(s)
Ryan P. Fitzgerald, Zeeshan Ahmed, Denis E. Bergeron, Nikolai Klimov, Dan Schmidt, Ronald Tosh
With the recent redefinition of the SI base units in terms of constants of nature, the race is on to maximize achievable precision by developing primary standards based on quantum metrology, thereby to realize the Quantum SI. For the becquerel (Bq) and

Limits on Strongly Interacting Sub-GeV Dark Matter from the PROSPECT Reactor Antineutrino Experiment

July 16, 2021
Author(s)
Hans Pieter Mumm, Denis E. Bergeron, Mark Tyra, Jerome LaRosa, Svetlana Nour, M Andriamirado, A.B. Balantekin, H.R. Band, C.D. Bass, D. Berish, N.S. Bowden, J.P. Brodsky, C.D. Bryan, T. Classen, A.J. Conant, G. Deichert, M.V. Diwan, M.J. Dolinski, A. Erickson, B.T. Foust, J.K. Gaison, A. Galindo-Uribarri, C.E. Gilbert, B.W. Goddard, B.T. Hackett, S. Hans, A.B. Hansell, K.M. Heeger, D.E. Jaffe, X. Ji, D.C. Jones, O. Kyzylova, C.E. Lane, T.J. Langford, B.R. Littlejohn, X. Lu, J. Maricic, M.P. Mendenhall, A.M. Meyer, R. Milincic, I. Mitchell, P.E. Mueller, J. Napolitano, C. Nave, R. Neilson, J.A. Nikkel, D. Norcini, J.L. Palomino, D.A. Pushin, X. Qian, E. Romero-Romero, R. Rosero, P.T. Surukuchi, R.L. Varner, D. Venegas-Vargas, P.B. Weatherly, C. White, J. Wilhelmi, A. Woolverton, M. Yeh, A. Zhang, C. Zhang, X. Zhang
If dark matter has mass lower than around 1 GeV, it will not impart enough energy to cause detectable nuclear recoils in many direct-detection experiments. However, if dark matter is upscattered to high energy by collisions with cosmic rays, it may be

Ra-224 activity, half-life, and 241 keV gamma ray absolute emission intensity: a NIST-NPL bilateral comparison

December 31, 2020
Author(s)
Denis E. Bergeron, Sean Collins, Leticia Pibida, Jeffrey T. Cessna, Ryan P. Fitzgerald, Brian E. Zimmerman, Peter Ivanov, John Keightley, Elisa Napoli
The national metrology institutes for the United Kingdom and the United States have compared activity standards for 224Ra, an -particle emitter of interest as the basis for therapeutic radiopharmaceuticals. Solutions of 224RaCl2 were assayed by absolute

The Next Generation of Current Measurement for Ionization Chambers

September 1, 2020
Author(s)
Ryan P. Fitzgerald, Denis E. Bergeron, Dean G. Jarrett, Neil M. Zimmerman, Carine Michotte, Hansjoerg Scherer, Stephen Giblin, Steven Judge
Re-entrant ionization chambers (ICs) are essential to radionuclide metrology and nuclear medicine for maintaining standards and measuring half-lives. Metrology-quality systems must be precise and stable to 0.1% over many years, and linear from 10^(-14) A

Ohms Law Low-current Calibration System for Ionization Chambers

August 24, 2020
Author(s)
Dean G. Jarrett, Shamith U. Payagala, Ryan P. Fitzgerald, Denis E. Bergeron, Jeffrey T. Cessna, Charles J. Waduwarage Perera, Neil M. Zimmerman
A system for the calibration of electrometers that measure currents from ionization chambers is described. The calibration system uses a 1 GΩ standard resistor in series with a stable voltage source to generate calibration currents from 1 pA to 20 nA

Non-fuel Antineutrino Contributions in the High Flux Isotope Reactor

May 14, 2020
Author(s)
PROSPECT COLLABORATION, Jerome LaRosa, Hans Pieter Mumm, Svetlana Nour, Mark Tyra, Denis E. Bergeron
Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties starting to surpass those from theory, it is important to carefully consider all sources of e in making theoretical predictions. One

228Th breakthrough in 224Ra samples: what can we know and when can we know it?

April 6, 2020
Author(s)
Denis E. Bergeron, Ryan P. Fitzgerald, Leticia S. Pibida
Recent renewed interest in radium-224 (224Ra) as a radiotherapeutic agent prompted the development of a primary standard for activity at the National Institute of Standards and Technology (NIST). The 224Ra decay chain includes the emission four alpha

Optimum lithium loading of a liquid scintillator for neutron and neutrino detection

February 11, 2020
Author(s)
Hans Pieter Mumm, Denis E. Bergeron, Mark Tyra, Jerome LaRosa, Svetlana Nour, T.J. Langford, Dimitry A. Pushin
Neutral particle detection in high-background environments is greatly aided by the ability to easily load 6Li into liquid scintillators. We describe a readily available and inexpensive liquid scintillation cocktail stably loaded with up to 1 % Li by mass