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Search Publications

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  • Published Date
Displaying 51 - 75 of 259

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

H2 Production in the 10B(n,?)7Li Reaction in Water

December 4, 2020
Author(s)
Alan K. Thompson, Travis C. Dietz, Mohamad Al-Sheikhly, Marcin Sterniczuk, David M. Bartels
We demonstrate a method for measuring the H2 produced in water from the 10B(n,α)7Li fission reaction. Low energy neutrons from the NIST Center for Neutron Research interact with borate- containing water in a temperature-controlled high pressure cell made

False Alarm Testing for Radiation Detection Systems

October 2, 2020
Author(s)
Dennis D. Leber, Leticia S. Pibida
An operator of a radiation detection system that displays a high rate of false alarms may be- come desensitized to these alarms. This action is known as alarm fatigue and can have detri- mental results as the operator may cease to respond to what may be

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

Effect of Teflon(R) Transmittance on Sensitivity of Thermoluminescence Dosimeter Cards

May 20, 2020
Author(s)
Vyacheslav B. Podobedov, Carl C. Miller, Alexander Romanyukha, Andrew Hoy
Thermoluminescence dosimeter cards purchased by the United States Navy in recent years have different radiation sensitivities, e.g. they exhibit a different amount of light per dose unit. Presented tests indicate that the optical transparency of the Teflon

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

Accurate Integral Counting Using Multi-channel Analyzers

May 1, 2020
Author(s)
Ryan P. Fitzgerald, Lynne E. King
Many techniques in radionuclide metrology rely on accurate measurement of the total count rate, that is integral counting, from a detector. In modern experiments, this can be achieved by integrating the total number of counts in an energy spectrum produced

Radiation damage of liquid electrolyte during focused X-ray beam photoelectron spectroscopy

April 12, 2020
Author(s)
Christopher M. Arble, Hongxuan Gou, Evgheni Strelcov, Brian D. Hoskins, Patrick Zeller, Matteo Amati, Luca Gregoratti, Andrei A. Kolmakov
Ambient pressure X-ray photoelectron spectroscopy (APXPS) has become an effective tool to interrogate chemical states at surfaces relevant to real operational conditions. Herein we employ a graphene-capped microvolume array sample platform for scanning

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

Low energy cross section measurement of the 10B(a;n)13N reaction and its impact on neutron production in 1st generation stars

February 26, 2020
Author(s)
Q Liu, M Febbraro, R.J. deBoer, S. Aguilar, A Boeltzig, Y Chen, M Couder, J Gorres, Jamie Weaver, K. T. Macon, M. Wiescher, K. Manukyan, L. Morales, S Pain, W. A. Peters, C. Seymour, G. Seymour, R. Toomey, B. Vande Kolk
Nucleosynthesis in the fi rst generation of massive stars offer a unique setting to explore the creation of the fi rst heavier nuclei in an environment free of impurities from earlier stellar generations. In later generations of massive stars, hydrogen

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

Field Compressed Sensing

January 17, 2020
Author(s)
Anthony B. Kos, Fabio C. Da Silva, Jason B. Coder, Craig W. Nelson, Grace E. Antonucci, Archita Hati
Imaging solutions based on wave scattering seek real-time performance, high dynamic range, and spatial accuracy at scales spanning from nanometers to thousands of kilometers. Compressed sensing algorithms use sparsity to reduce sample size during image

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

Feasibility Study of Compton Imaging for PGAA

October 1, 2019
Author(s)
Heather H. Chen-Mayer, Steven Brown, Hao Yang
We are developing a one-sided tomographic method for imaging prompt gamma rays, without moving the source, sample, or detector, in a standard prompt gamma activation analysis (PGAA) setting. Dual-plane pixelated CZT detectors developed from a commercial

Measurement of the 10B(?,n0)13N cross section at E? ? 3.6 MeV and its application as a diagnostic at the National Ignition Facilit

September 3, 2019
Author(s)
Q Liu, M Febbraro, R.J. deBoer, A Boeltzig, Y Chen, C Cerjan, M Couder, B Frentz, G Gilardy, J. Gorres, E. A. Henry, E. Lamere, K. T. Macon, K. Manukyan, L. Morales, P. D. O'Malley, S Pain, W. A. Peters, D. Schneider, C. Seymour, R. Toomey, B. Vande Kolk, Jamie Weaver, M. Wiescher
The National Ignition Facility provides the opportunity to study nuclear reactions under controlled conditions at high temperatures and pressures at a level never before achieved. However, the time scale of the DT implosion is only a few nanoseconds

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
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