U.S. flag

An official website of the United States government

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.

Search Publications by: Denis E. Bergeron (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 139

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

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

Primary standardization of Ra-224 activity by liquid scintillation counting

October 11, 2019
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 confirmed by efficiency tracing and 4παβ(LS)-γ(NaI(Tl)) anticoincidence counting, as well as by 4πγ

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

August 9, 2019
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-double coincidence ratio (TDCR) and CIEMAT-NIST efficiency tracing (CNET) liquid scintillation