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Displaying 76 - 100 of 244

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

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

A Precision Measurement of the Neutron Scattering Length of4He Using Neutron Interferometry

January 7, 2020
Author(s)
Robert W. Haun, Fred Wietfeldt, Muhammad D. Arif, Michael G. Huber, T C. Black, Ben Heacock, Dmitry Pushin, Chandra B. Shahi
We report a 0.08% measurement of the bound neutron scattering length of 4He using neutron interferometry. The result is b=(3.0982 ± 0.0021[stat] ± 0.0014[syst]) fm. The corresponding free atomic scattering length is a=(2.4746 ± 0.0017[stat] ± 0.0011[syst])

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

Study of the neutron spin-orbit interaction in silicon

September 29, 2019
Author(s)
Thomas R. Gentile, Michael G. Huber, Muhammad D. Arif, Daniel Hussey, David Jacobson, Donald D. Koetke, Murray Peshkin, Thomas Dombeck, Paul Nord, Dimitry A. Pushin, Robert Smither
The neutron spin-orbit interaction, which results from the interaction of a moving neutron's magnetic dipole moment (MDM) with the atomic electric fields, induces a small rotation of the neutron's spin in one Bragg reflection. In our experiment neutrons

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

Ampoules for Radioactivity Standard Reference Materials

August 6, 2019
Author(s)
Ronald Colle
Standard-sized ampoules for radioactive solution standards have been employed by the National Institute of Standards and Technology (NIST) for nearly the past 70 years. This note briefly summarizes the origins and history of the five different batches of

Experimental Upper Bound and Theoretical Expectations for Parity-Violating Neutron Spin Rotation in He-4

July 16, 2019
Author(s)
Jeffrey S. Nico, Hans P. Mumm, H E. Swanson, C. D. Bass, T. D. Bass, J M. Dawkins, J C. Horton, D Luo, William M. Snow, S. C. Walbridge, B. E. Crawford, K. F. Gan, A M. Micherdzinska, C. R. Huffer, D M. Markoff, Murad Sarsour, E I. Sharapov, V Zhumabekova, Blayne R. Heckel
Neutron spin rotation is expected from quark-quark weak interactions in the Standard Model, which induce weak interactions among nucleons that violate parity. We present the results from an experiment searching for the effect of parity violation via the
Displaying 76 - 100 of 244