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Search Publications by: Alan Keith Thompson (Fed)

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Displaying 1 - 25 of 98

H2 Generation by the 10B(n,alpha)7Li Reaction in High Temperature Water

July 4, 2023
Author(s)
Alan Keith Thompson, Mohamad Al-Sheikhly, Steven Guerin, David Bartels, Cameron Goodwin, Sangho Nam
H2 produced in water from the 10B(n,α)7Li fission reaction has been measured up to 300 oC. Thermal energy neutrons from the Rhode Island Nuclear Science Center's 2 MW reactor interact with boric acid-containing water in temperature-controlled high-pressure

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

Design of an Ultrathin Cold Neutron Detector

June 11, 2018
Author(s)
A. Osovizky, Kevin N. Pritchard, Y. Yehuda-Zada, Jeffrey B. Ziegler, Louis E. Binkley, Peter NMN Tsai, Alan Keith Thompson, Nancy Hadad, George M. Baltic, M. Jackson, C. Hurlbut, Charles Majkrzak, Nicholas C. Maliszewskyj
WE describe the designs, fabrication, and performance of an energy analyzing detector package for cold neutron spectrometers at the NIST Center for Neutron Research. The detector package consists of arrays of highly oriented pyrolytic graphite crystals set

Design of an Ultrathin Cold Neutron Detector

June 11, 2018
Author(s)
A. Osovizky, Kevin N. Pritchard, Y. Yehuda-Zada, Jeffrey B. Ziegler, Louis E. Binkley, Peter NMN Tsai, Alan Keith Thompson, Nancy Hadad, M. Jackson, C. Hurlbut, George M. Baltic, Charles Majkrzak, Nicholas C. Maliszewskyj
We describe the design and performance of an ultrathin ( 2mm) cold neutron proportional counter consisting of 6LiF:ZnS(Ag) scintillator in which wavelength shifting fibers have been embedded to conduct scintillation photons out of the medium to a silicon

Selection of Silicon Photomultipliers for a 6 LiF:ZnS(Ag) Scintillator Based Cold Neutron Detector

April 8, 2018
Author(s)
A. Osovizky, Kevin N. Pritchard, Y. Yehuda-Zada, Jeffrey B. Ziegler, Peter NMN Tsai, M. Ghelman, Alan Keith Thompson, R. M. Ibberson, George M. Baltic, Charles Majkrzak, Nicholas C. Maliszewskyj
We describe the process of selecting a silicon photomultiplier (SiPM) as the light sensor for an ultrathin (2 nm) highly efficient cold neutron proportional counter. The neutron detector consists of 6LiF:ZnS(Ag) scintillator in which wavelength shifting

6 LiF:ZnS(Ag) Mixture Optimization for a Miniature Highly Efficient Cold Neutron Detector

April 2, 2018
Author(s)
A. Osovizky, Kevin N. Pritchard, Jeffrey B. Ziegler, Louis E. Binkley, Y. Yehuda-Zada, Peter NMN Tsai, Alan Keith Thompson, P. Yvonne Barnes, Kerry Siebein, Nancy Hadad, M. Jackson, C. Hurlbut, R. Ibberson, George M. Baltic, Charles Majkrzak, Nicholas C. Maliszewskyj
We report the optimization of a ^6^LiF:ZnS(Ag) scintillator mixture for an ultrathin (2nm), highly efficient cold neutron dector. Preliminary results with early protypes demonstrate excellent for 3.62 meV (4.75 Angstrom wavelenght) neutrons but mediocre

Performance evolution of TLD-700H/600H dosimetry system at extended issue periods

December 15, 2017
Author(s)
Alexander A. Romanyukha, Matthew Grypp, F. Trompier, Alan Keith Thompson, Ronaldo Minniti, Jacque Debroas, Anthony S. Williams
Results of a comprehensive study of the TLD-700H/600H dosimetry system performance for an extended issue period are presented and discussed. It was concluded that the obtained results provide a technical justification to use the current dosimetry system at

Precision measurement of the radiative beta decay of the free neutron

June 30, 2017
Author(s)
Christopher D. Bass, Maynard S. Dewey, Thomas R. Gentile, Hans Pieter Mumm, Alan Keith Thompson, M J. Bales, R. Alarcon, E J. Beise, H Breuer, Jim Byrne, T E. Chupp, Kevin Coakley, R L. Cooper, B. O'Neill, F E. Wietfeldt
The theory of quantum electrodynamics predicts that a continuous spectrum of photons is emitted in the beta decay of the free neutron in addition to a proton, an electron, and an antineutrino. We report the first precision test of the shape of the photon

Precision measurement of the radiative beta decay of the free neutron

June 14, 2016
Author(s)
Jeffrey S. Nico, Kevin J. Coakley, Maynard S. Dewey, Thomas R. Gentile, Hans P. Mumm, Alan Keith Thompson, M J. Bales, R. Alarcon, C. D. Bass, E J. Beise, H Breuer, Jim Byrne, R L. Cooper, B. O'Neill, F E. Wietfeldt, T E. Chupp
The theory of quantum electrodynamics predicts that a continuous spectrum of photons is emitted in the beta decay of the free neutron in addition to a proton, an electron, and an antineutrino. We report the first precision test of the shape of the photon

Survival analysis approach to account for non-exponential decay rate effects in lifetime experiments

January 13, 2016
Author(s)
Kevin J. Coakley, Maynard S. Dewey, Michael G. Huber, Hans P. Mumm, Alan Keith Thompson, Andrew T. Yue, C. R. Huffer, P. R. Huffman, C. M. O'Shaughnessy, K. W. Schelhammer, D. E. Marley
In experiments that measure the lifetime of trapped particles, in addition to loss mechanisms with exponential survival probability functions, particles can be lost by mechanisms with non-exponential survival probability functions. Failure to account for

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons

May 1, 2014
Author(s)
Hans P. Mumm, Alan Keith Thompson, Paul R. Huffman, Christopher O'Shaughnessy, Kevin J. Coakley, Robert Golub, John M. Doyle, Steve K. Lamoreaux, P.-N. Seo, C E. Mattoni, S N. Dzhosyuk, L Yang, Grace L. Yang, Karl W. Schelhammer, Christopher M. Swank
The neutron beta-decay lifetime plays an important role, both in understanding weak interactions within the framework of the Standard Model, and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we

Noble Gas Excimer Scintillation Following Neutron Capture in Boron Thin Films

April 11, 2014
Author(s)
Alan K. Thompson, Jacob McComb, Charles W. Clark, Michael A. Coplan, Mohamad Al-Sheikhly, Robert E. Vest
Far-ultraviolet (FUV) scintillation signals have been measured in heavy noble gases (argon, krypton, xenon) following boron-neutron capture (10B(n,α)7Li) in 10B thin films. The observed scintillation yields are comparable to the yields from some liquid and

Search for a T-odd, P-even Triple Correlation in Neutron Decay

September 14, 2012
Author(s)
Jeffrey S. Nico, T E. Chupp, K P. Coulter, R L. Cooper, S. J. Freeman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Hans P. Mumm, Alan K. Thompson, C A. Trull, F. E. Wiefeldt, J. F. Wilkerson
Time-reversal-invariance (T) violation, or equivalently, assuming charge-conjugation-parity-time-reversal (CPT) invariance, CP violation may explain the observed cosmological baryon asymmetry as well as signal physics beyond the Standard Model. In the

A New Limit on Time-Reversal Violation in Beta Decay

September 2, 2012
Author(s)
Hans P. Mumm, T E. Chupp, K P. Coulter, R L. Cooper, S J. Freedman, B. K. Fujikawa, A. Garcia, Gordon L. Jones, Jeffrey S. Nico, Alan K. Thompson, C A. Trull, J. F. Wilkerson, F. E. Wiefeldt
We report the results of an improved determination of the triple correlation DP • (p_e × p_v) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the Standard Model. Our result is

A gamma and X-ray dector for cryogenic, high magnetic field applications

July 13, 2012
Author(s)
Thomas R. Gentile, R L. Cooper, R. Alarcon, M J. Bales, E J. Beise, H Breuer, J. Byrne, T E. Chupp, Kevin J. Coakley, Maynard S. Dewey, Changbo Fu, Hans P. Mumm, Jeffrey S. Nico, B. O'Neill, K. Pulliam, Alan Keith Thompson, F E. Wietfeldt
As part of an experiment to measure the spectrum of photons emitted in beta-decay of the free neu- tron, we developed and operated a detector consisting of 12 bismuth germanate (BGO) crystals coupled to avalanche photodiodes (APDs). The detector was

Effect of Neutron Irradiation on Dosimetric Properties of the TLD-600H (Lif6:Mg,Cu,P)

November 1, 2011
Author(s)
Alexander A. Romanyukha, Ronaldo Minniti, M. Moscovitch, Alan Keith Thompson, F. Trompier, Ronald Colle, A Sucheta, S. P. Voss, L. A. Benevides
Ideally, dosimeters should measure the dose without their dosimetric properties being affected by the radiation type being measured. Industry-wide occupational radiation workers that can be potentially exposed to neutron radiation fields are routinely

Fast Neutron Detection with Li-6-loaded Liquid Scintillator

April 12, 2011
Author(s)
David M. Gilliam, B Fisher, J N. Abdurashitov, Kevin Coakley, V N. Gavrin, Jeffrey S. Nico, A A. Shikhin, Alan Keith Thompson, Dominic F. Vecchia, V E. Yants
We report on the development of a fast neutron detector using a liquid scintillator doped with enriched 6Li. The lithium was introduced in the form of an aqueous LiCl micro-emulsion with a di-isopropylnaphthalene based liquid scintillator. A 6Li

Far-ultraviolet signatures of the 3He(n,tp) reaction in noble gas mixtures

December 8, 2010
Author(s)
Patrick Hughes, Alan K. Thompson, Michael Coplan, Robert E. Vest, Charles W. Clark
Previous work showed that the 3He(n,tp) reaction in a cell of 3He at atmospheric pressure generated tens of far-ultraviolet photons per reacted neutron. Here we report amplification of that signal by factors of 1000 and more when noble gases are added to

An experiment for the precision measurement of the radiative decay mode of the neutron

October 5, 2009
Author(s)
R Cooper, Christopher D. Bass, E Beise, H Breuer, Jim Byrne, T E. Chupp, Kevin Coakley, Maynard S. Dewey, B Fisher, Changbo Fu, Thomas R. Gentile, M. McGonagle, Hans Pieter Mumm, Jeffrey S. Nico, Alan Keith Thompson, F E. Wietfeldt
The neutron typically beta decays into a proton, electron, and antineutrino. In some decays, it can be accompanied by a high energy photon. We recently performed the rst observation of the radiative beta decay branch for the free neutron with photons of

Radiative Beta Decay of the Free Neutron

February 2, 2009
Author(s)
R L. Cooper, T E. Chupp, Maynard S. Dewey, Thomas R. Gentile, Hans Pieter Mumm, Jeffrey S. Nico, Alan Keith Thompson, B M. Fisher, I Kremsky, F E. Wietfeldt, E J. Beise, H Breuer, K G. Kiriluk, J Bryne, Kevin Coakley, Changbo Fu
The theory of quantum electrodynamics predicts that the beta decay of the neutron into a proton, electron, and antineutrino is accompanied by a continuous spectrum of emitted photons described as inner bremsstrahlung. While this phenomenon has been

Particle and Photon Detection for a Neutron Radiative Decay Experiment

April 11, 2007
Author(s)
Thomas R. Gentile, Maynard S. Dewey, Hans P. Mumm, Jeffrey S. Nico, Alan K. Thompson, T E. Chupp, R Cooper, B M. Fisher, I Kremsky, F E. Wietfeldt, K G. Kiriluk, E Beise
We present the particle and photon detection methods employed in a program to observe neutron radiative beta-decay. The experiment is located at the NG-6 beam line at the National Institute of Standards and Technology Center for Neutron Research. Electrons