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Atomic, Molecular and Optical Physics

Selected Works

Robert W. Pattie Jr.

Articles 1 - 17 of 17

Full-Text Articles in Physics

Solid Deuterium Surface Degradation At Ultracold Neutron Sources, Alexander Anghel, Thomas L. Bailey, George Bison, Bertrand Blau, Leah J. Broussard, Stephen M. Clayton, Christopher Cude-Woods, Manfred Daum, Ayman I. Hawari, Nora Hild, Paul R. Huffman, Takeyasu M. Ito, Klaus Kirch, E. Korobkina, Bernhard Lauss, Kent Leung, E. M. Lutz, Mark Makela, G. Medlin, C. L. Morris, Robert W. Pattie, Dieter Ries, Alexander Saunders, Phillip Schmidt-Wellenburg, Vadim Talanov, Albert R. Young, Bernard Wehring, C. White, Michael Wohlmuther, Geza Zsigmond Aug 2018

Solid Deuterium Surface Degradation At Ultracold Neutron Sources, Alexander Anghel, Thomas L. Bailey, George Bison, Bertrand Blau, Leah J. Broussard, Stephen M. Clayton, Christopher Cude-Woods, Manfred Daum, Ayman I. Hawari, Nora Hild, Paul R. Huffman, Takeyasu M. Ito, Klaus Kirch, E. Korobkina, Bernhard Lauss, Kent Leung, E. M. Lutz, Mark Makela, G. Medlin, C. L. Morris, Robert W. Pattie, Dieter Ries, Alexander Saunders, Phillip Schmidt-Wellenburg, Vadim Talanov, Albert R. Young, Bernard Wehring, C. White, Michael Wohlmuther, Geza Zsigmond

Robert W. Pattie Jr.

Solid deuterium (sD  is used as an efficient converter to produce ultracold neutrons (UCN). It is known that the sD must be sufficiently cold, of high purity and mostly in its ortho-state in order to guarantee long lifetimes of UCN in the solid from which they are extracted into vacuum. Also the UCN transparency of the bulk sD  material must be high because crystal inhomogeneities limit the mean free path for elastic scattering and reduce the extraction efficiency. Observations at the UCN sources at Paul Scherrer Institute and at Los Alamos National Laboratory consistently show a decrease of the UCN …

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Search For The Neutron Decay N → X + Γ , Where X Is A Dark Matter Particle, Zhoawen Tang, Marie Blatnik, Leah J. Broussard, J. H. Choi, Stephen M. Clayton, Christopher Cude-Woods, Scott Currie, D. E. Fellers, E. M. Fries, Peter Geltenbort, F. Gonzalez, Kevin P. Hickerson, Takeyasu M. Ito, Chen Y. Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, C. M. O'Shaughnessy, Robert W. Pattie Jr., Bradley R. Plaster, D. J. Salvat, Alexander Saunders, Zhehui Wang, Albert R. Young, B. A. Zeck Jul 2018

Search For The Neutron Decay N → X + Γ , Where X Is A Dark Matter Particle, Zhoawen Tang, Marie Blatnik, Leah J. Broussard, J. H. Choi, Stephen M. Clayton, Christopher Cude-Woods, Scott Currie, D. E. Fellers, E. M. Fries, Peter Geltenbort, F. Gonzalez, Kevin P. Hickerson, Takeyasu M. Ito, Chen Y. Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, C. M. O'Shaughnessy, Robert W. Pattie Jr., Bradley R. Plaster, D. J. Salvat, Alexander Saunders, Zhehui Wang, Albert R. Young, B. A. Zeck

Robert W. Pattie Jr.

Fornal and Grinstein recently proposed that the discrepancy between two different methods of neutron lifetime measurements, the beam and bottle methods, can be explained by a previously unobserved dark matter decay mode, n→X+γ. We perform a search for this decay mode over the allowed range of energies of the monoenergetic γ ray for X to be dark matter. A Compton-suppressed high-purity germanium detector is used to identify γ rays from neutron decay in a nickel-phosphorous-coated stainless-steel bottle. A combination of Monte Carlo and radioactive source calibrations is used to determine the absolute efficiency for detecting γ …

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Measurement Of The Neutron Lifetime Using A Magneto-Gravitational Trap And In Situ Detection, Robert W. Pattie Jr., Nathan B. Callahan, Chris Cude-Woods, Edith R. Adamek, Leah J. Broussard, Stephen M. Clayton, Scott A. Currie, Eric B. Dees, Xiaoping Ding, Egbert M. Engel, D. E. Fellers, William Fox, Peter Geltenbort, Kevin P. Hickerson, Mark A. Hoffbauer, Anthony T. Holley, A. Komives, Chen Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, Joseph D. Ortiz, John C. Ramsey, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, E. I. Sharapov, S. K. Sjue, Zebo Tang, J. Vanderwerp, Bruce Vogelaar, P. L. Walstrom, Zhehui Wang, Wei Wei, H. L. Weaver, Judith W. Wexler, Tanner L. Womack, Andrew R. Young, B. A. Zeck May 2018

Measurement Of The Neutron Lifetime Using A Magneto-Gravitational Trap And In Situ Detection, Robert W. Pattie Jr., Nathan B. Callahan, Chris Cude-Woods, Edith R. Adamek, Leah J. Broussard, Stephen M. Clayton, Scott A. Currie, Eric B. Dees, Xiaoping Ding, Egbert M. Engel, D. E. Fellers, William Fox, Peter Geltenbort, Kevin P. Hickerson, Mark A. Hoffbauer, Anthony T. Holley, A. Komives, Chen Liu, S. W. T. Macdonald, Mark Makela, Christopher L. Morris, Joseph D. Ortiz, John C. Ramsey, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, E. I. Sharapov, S. K. Sjue, Zebo Tang, J. Vanderwerp, Bruce Vogelaar, P. L. Walstrom, Zhehui Wang, Wei Wei, H. L. Weaver, Judith W. Wexler, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

The precise value of the mean neutron lifetime, tn, plays an important role in nuclear and particle physics and cosmology. It is used to predict the ratio of protons to helium atoms in the primordial universe and to search for physics beyond the Standard Model of particle physics. We eliminated loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls. As a result of this approach and the use of an in …

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Performance Of The Upgraded Ultracold Neutron Source At Los Alamos National Laboratory And Its Implication For A Possible Neutron Electric Dipole Moment Experiment, Takeyasu M. Ito, Evan R. Adamek, Nathan B. Callahan, J. H. Choi, Stephen M. Clayton, Chris Cude-Woods, Scott Currie, Xinjian Ding, D. E. Fellers, Peter Geltenbort, Steve K. Lamoreaux, C. Y. Liu, S. Macdonald, Mark Makela, Charles L. Morris, Robert W. Pattie Jr., John Clinton Ramsey, Daniel J. Salvat, Andy Saunders, Edward I. Sharapov, S. Sjue, A. P. Sprow, Zebo Tang, H. L. Weaver, Wanchun Wei, Andrew R. Young Jan 2018

Performance Of The Upgraded Ultracold Neutron Source At Los Alamos National Laboratory And Its Implication For A Possible Neutron Electric Dipole Moment Experiment, Takeyasu M. Ito, Evan R. Adamek, Nathan B. Callahan, J. H. Choi, Stephen M. Clayton, Chris Cude-Woods, Scott Currie, Xinjian Ding, D. E. Fellers, Peter Geltenbort, Steve K. Lamoreaux, C. Y. Liu, S. Macdonald, Mark Makela, Charles L. Morris, Robert W. Pattie Jr., John Clinton Ramsey, Daniel J. Salvat, Andy Saunders, Edward I. Sharapov, S. Sjue, A. P. Sprow, Zebo Tang, H. L. Weaver, Wanchun Wei, Andrew R. Young

Robert W. Pattie Jr.

The ultracold neutron (UCN) source at Los Alamos National Laboratory (LANL), which uses solid deuterium as the UCN converter and is driven by accelerator spallation neutrons, has been successfully operated for over 10 years, providing UCN to various experiments, as the first production UCN source based on the superthermal process. It has recently undergone a major upgrade. This paper describes the design and performance of the upgraded LANL UCN source. Measurements of the cold neutron spectrum and UCN density are presented and compared to Monte Carlo predictions. The source is shown to perform as modeled. The UCN density measured at …

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A New Method For Measuring The Neutron Lifetime Using An In Situ Neutron Detector, Christopher L. Morris, Edith R. Adamek, Leah J. Broussard, Nathan B. Callahan, Stephen M. Clayton, Chris Cude-Woods, Scott A. Currie, Xiaoping Ding, Walter Fox, Kevin P. Hickerson, Mark A. Hoffbauer, Anthony T. Holley, A. Komives, Chen Y. Liu, Mark Makela, Robert W. Pattie, John C. Ramsey, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, E. I. Sharapov, S. K. Sjue, Zhijing Tang, J. Vanderwerp, R. Bruce Vogelaar, Peter L. Walstrom, Zhehui Wang, Wanchun Wei, Judith W. Wexler, Tanner L. Womack, Andrew R. Young, B. A. Zeck May 2017

A New Method For Measuring The Neutron Lifetime Using An In Situ Neutron Detector, Christopher L. Morris, Edith R. Adamek, Leah J. Broussard, Nathan B. Callahan, Stephen M. Clayton, Chris Cude-Woods, Scott A. Currie, Xiaoping Ding, Walter Fox, Kevin P. Hickerson, Mark A. Hoffbauer, Anthony T. Holley, A. Komives, Chen Y. Liu, Mark Makela, Robert W. Pattie, John C. Ramsey, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, E. I. Sharapov, S. K. Sjue, Zhijing Tang, J. Vanderwerp, R. Bruce Vogelaar, Peter L. Walstrom, Zhehui Wang, Wanchun Wei, Judith W. Wexler, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

In this paper, we describe a new method for measuring surviving neutrons in neutron lifetime measurements using bottled ultracold neutrons (UCN), which provides better characterization of systematic uncertainties and enables higher precision than previous measurement techniques. An active detector that can be lowered into the trap has been used to measure the neutron distribution as a function of height and measure the influence of marginally trapped UCN on the neutron lifetime measurement. In addition, measurements have demonstrated phase-space evolution and its effect on the lifetime measurement.

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Detection System For Neutron Β Decay Correlations In The Ucnb And Nab Experiments, Leah J. Broussard, B. A. Zeck, Edith R. Adamek, Stephan Baeßler, Noah Birge, Marie Blatnik, J. David Bowman, Astrid E. Brandt, A. E. Brandt, Matthew Brown, John F. Burkhart, Nathan B. Callahan, Steven M. Clayton, Christopher B. Crawford, Chris Cude-Woods, Scott Currie, Eric B. Dees, Xinjian Ding, Nadia Fomin, Emil Frlez, Jason Fry, Frederick E. Gray, Said Hasan, Kevin P. Hickerson, J. Todd Hoagland, Anthony T. Holley, Takeyasu M. Ito, Andreas Klein, Hengne Li, Chenyu Liu, Mark F. Makela, P. L. Mcgaughey, J. Mirabal-Martinez, Charles L. Morris, Jose D. Ortiz, Robert W. Pattie Jr., Seppo I. Penttilä, Brad Plaster, Dinko Počanić, John C. Ramsey, A. Salas-Bacci, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, Sky Sjue, Aron Sprow, Z. Tang, R. Bruce Vogelaar, Brittany Vorndick, Z. Wang, Wanchun Wei, J. Wexler, W. S. Wilburn, T. L. Womack, A. R. Young Mar 2017

Detection System For Neutron Β Decay Correlations In The Ucnb And Nab Experiments, Leah J. Broussard, B. A. Zeck, Edith R. Adamek, Stephan Baeßler, Noah Birge, Marie Blatnik, J. David Bowman, Astrid E. Brandt, A. E. Brandt, Matthew Brown, John F. Burkhart, Nathan B. Callahan, Steven M. Clayton, Christopher B. Crawford, Chris Cude-Woods, Scott Currie, Eric B. Dees, Xinjian Ding, Nadia Fomin, Emil Frlez, Jason Fry, Frederick E. Gray, Said Hasan, Kevin P. Hickerson, J. Todd Hoagland, Anthony T. Holley, Takeyasu M. Ito, Andreas Klein, Hengne Li, Chenyu Liu, Mark F. Makela, P. L. Mcgaughey, J. Mirabal-Martinez, Charles L. Morris, Jose D. Ortiz, Robert W. Pattie Jr., Seppo I. Penttilä, Brad Plaster, Dinko Počanić, John C. Ramsey, A. Salas-Bacci, Daniel J. Salvat, Alexander Saunders, Susan J. Seestrom, Sky Sjue, Aron Sprow, Z. Tang, R. Bruce Vogelaar, Brittany Vorndick, Z. Wang, Wanchun Wei, J. Wexler, W. S. Wilburn, T. L. Womack, A. R. Young

Robert W. Pattie Jr.

We describe a detection system designed for precise measurements of angular correlations in neutron β decay. The system is based on thick, large area, highly segmented silicon detectors developed in collaboration with Micron Semiconductor, Ltd. The prototype system meets specifications for β electron detection with energy thresholds below 10 keV, energy resolution of ∼3 keV FWHM, and rise time of ∼50 ns with 19 of the 127 detector pixels instrumented. Using ultracold neutrons at the Los Alamos Neutron Science Center, we have demonstrated the coincident detection of β particles and recoil protons from neutron β decay. The fully instrumented detection system will be …

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Position-Sensitive Detection Of Ultracold Neutrons With An Imaging Camera And Its Implications To Spectroscopy, Wanchun Wei, Leah J. Broussard, Mark A. Hoffbauer, Mark Makela, Charles L. Morris, Zebo Tang, Evan R. Adamek, Nathan B. Callahan, Stephen M. Clayton, Chris Cude-Woods, Scott Currie, Eric B. Dees, Xinjian Ding, Peter Geltenbort, Kevin P. Hickerson, Anthony T. Holley, Takeyasu M. Ito, Kent K. Leung, Chenyu Y. Liu, Deborah J. Morley, Jose D. Ortiz, Robert W. Pattie, John C. Ramsey, Alexander Saunders, Susan J. Seestrom, Eduard I. Sharapov, S. K. Sjue, Judith Wexler, Tanner L. Womack, Albert R. Young, B. A. Zeck, Zhehui Wang Sep 2016

Position-Sensitive Detection Of Ultracold Neutrons With An Imaging Camera And Its Implications To Spectroscopy, Wanchun Wei, Leah J. Broussard, Mark A. Hoffbauer, Mark Makela, Charles L. Morris, Zebo Tang, Evan R. Adamek, Nathan B. Callahan, Stephen M. Clayton, Chris Cude-Woods, Scott Currie, Eric B. Dees, Xinjian Ding, Peter Geltenbort, Kevin P. Hickerson, Anthony T. Holley, Takeyasu M. Ito, Kent K. Leung, Chenyu Y. Liu, Deborah J. Morley, Jose D. Ortiz, Robert W. Pattie, John C. Ramsey, Alexander Saunders, Susan J. Seestrom, Eduard I. Sharapov, S. K. Sjue, Judith Wexler, Tanner L. Womack, Albert R. Young, B. A. Zeck, Zhehui Wang

Robert W. Pattie Jr.

Position-sensitive detection of ultracold neutrons (UCNs) is demonstrated using an imaging charge-coupled device (CCD) camera. A spatial resolution less than 15μmhas been achieved, which is equivalent to a UCN energy resolution below 2 pico-electron-volts through the relation δE=m0gδx. Here, the symbols δE, δx, m0 and gare the energy resolution, the spatial resolution, the neutron rest mass and the gravitational acceleration, respectively. A multilayer surface convertor described previously is used to capture UCNs and then emits visible light for CCD imaging. Particle identification and noise rejection are discussed through the use of light intensity profile …

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Measurement Of Spin-Flip Probabilities For Ultracold Neutrons Interacting With Nickel Phosphorus Coated Surfaces, Zhaowen Tang, Evan Robert Adamek, Aaron Brandt, Nathan Brannan Callahan, Steven M. Clayton, Scott Allister Currie, Takeyasu M. Ito, Mark F. Makela, Yasuhiro Masuda, Christopher L. Morris, Robert Wayne Pattie, John Clinton Ramsey, Daniel J. Salvat, Daniel J. Salvat, Alexander Saunders, Albert R. Young Aug 2016

Measurement Of Spin-Flip Probabilities For Ultracold Neutrons Interacting With Nickel Phosphorus Coated Surfaces, Zhaowen Tang, Evan Robert Adamek, Aaron Brandt, Nathan Brannan Callahan, Steven M. Clayton, Scott Allister Currie, Takeyasu M. Ito, Mark F. Makela, Yasuhiro Masuda, Christopher L. Morris, Robert Wayne Pattie, John Clinton Ramsey, Daniel J. Salvat, Daniel J. Salvat, Alexander Saunders, Albert R. Young

Robert W. Pattie Jr.

We report a measurement of the spin-flip probabilities for ultracold neutrons interacting with surfaces coated with nickel phosphorus. For 50 μm thick nickel phosphorus coated on stainless steel, the spin-flip probability per bounce was found to be βNiPonSS=(3.3−5.6+1.8)×10−6. For 50 μm thick nickel phosphorus coated on aluminum, the spin-flip probability per bounce was found to be βNiPonAl=(3.6−5.9+2.1)×10−6. For the copper guide used as reference, the spin flip probability per bounce was found to be βCu=(6.7−2.5+5.0)×10−6. The results on the nickel phosphorus-coated surfaces may be interpreted as upper limits, yielding βNiPonSS<6.2×10−6 (90% C.L.) and βNiPonAl<7.0×10−6 (90% C.L.) for 50 μm thick …

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A Multilayer Surface Detector For Ultracold Neutrons Sep 2015

A Multilayer Surface Detector For Ultracold Neutrons

Robert W. Pattie Jr.

A multilayer surface detector for ultracold neutrons (UCNs) is described. The top 10B layer is exposed to the vacuum chamber and directly captures UCNs. The ZnS:Ag layer beneath the 10B layer is a few microns thick, which is sufficient to detect the charged particles from the 10B(n,α)7Li neutron-capture reaction, while thin enough so that ample light due to α and 7Li escapes for detection by photomultiplier tubes. One-hundred-nm thick 10B layer gives high UCN detection efficiency, as determined by the mean UCN kinetic energy, detector materials and others. Low background, including …

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Characterization Of Large Area, Thick, And Segmented Silicon Detectors For Neutron Β-Decay Experiments, Americo Salas-Bacci, Patrick L. Mcgaughey, Stephan Baeßler, Leah Broussard, Mark F. Makela, J. Mirabal, Robert W. Pattie, Dinko Počanić, Sky K.L. Sjue, Seppo I. Penttila, Wesley S. Wilburn, Albert R. Young, B.A. Zeck, Zhehui Wang Dec 2013

Characterization Of Large Area, Thick, And Segmented Silicon Detectors For Neutron Β-Decay Experiments, Americo Salas-Bacci, Patrick L. Mcgaughey, Stephan Baeßler, Leah Broussard, Mark F. Makela, J. Mirabal, Robert W. Pattie, Dinko Počanić, Sky K.L. Sjue, Seppo I. Penttila, Wesley S. Wilburn, Albert R. Young, B.A. Zeck, Zhehui Wang

Robert W. Pattie Jr.

The “Nab” and “UCNB” collaborations have proposed to measure the correlation parameters in neutron β-decay at Oak Ridge and Los Alamos National Laboratory, using a novel detector design. Two large area, thick, hexagonal-segmented silicon detectors containing 127 pixels per detector will be used to detect the proton and electron from neutron decay. Both silicon detectors are connected by magnetic field lines of a few Tesla field strength, and set on an electrostatic potential, such that protons can be accelerated up to 30 keV in order to be detected. Characteristics of the detector response to low energy conversion electrons and protons from …

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The Upscattering Of Ultracold Neutrons From The Polymer (C6h12)N, Eduard I. Sharapov, Christopher L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Leah J. Broussard, Chris B. Cude-Woods, Deion E. Fellers, Peter Geltenbort, Monika Hartl, Siraj I. Hasan, Kevin P. Hickerson, Gary E. Hogan, Anthony T. Holley, C. M. Lavelle, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie, David G. Phillips, John Ramsey, Daniel J. Salvat, Susan J. Seestrom, Erik Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck Dec 2013

The Upscattering Of Ultracold Neutrons From The Polymer (C6h12)N, Eduard I. Sharapov, Christopher L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Leah J. Broussard, Chris B. Cude-Woods, Deion E. Fellers, Peter Geltenbort, Monika Hartl, Siraj I. Hasan, Kevin P. Hickerson, Gary E. Hogan, Anthony T. Holley, C. M. Lavelle, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie, David G. Phillips, John Ramsey, Daniel J. Salvat, Susan J. Seestrom, Erik Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

It is generally accepted that the main cause of ultracold neutron (UCN) losses in storage traps is upscattering to the thermal energy range by hydrogen adsorbed on the surface of the trap walls. However, the data on which this conclusion is based are poor and contradictory. Here we report a measurement, performed at the Los Alamos National Laboratory UCN source, of the average energy of the flux of upscattered neutrons after the interaction of UCN with hydrogen bound in the semicrystalline polymer PMP (trade name TPX), [C6H12]n. Our analysis, performed with the mcnp code which applies …

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Measurements Of Ultracold Neutron Upscattering And Absorption In Polyethylene And Vanadium, Eduard I. Sharapov, Charles L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Yelena Bagdasarova, Leah J. Broussard, Chris Cude-Woods, Deon E. Fellers, Peter Geltenbort, Siraj I. Hasan, Kevin P. Hickerson, Gary Hogan, Anthony T. Holley, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie Jr., David G. Phillips, John Ramsey, D. J. Salvat, Susan J. Seestrom, E. Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck Sep 2013

Measurements Of Ultracold Neutron Upscattering And Absorption In Polyethylene And Vanadium, Eduard I. Sharapov, Charles L. Morris, Mark Makela, Andy Saunders, Evan R. Adamek, Yelena Bagdasarova, Leah J. Broussard, Chris Cude-Woods, Deon E. Fellers, Peter Geltenbort, Siraj I. Hasan, Kevin P. Hickerson, Gary Hogan, Anthony T. Holley, Chen-Yu Liu, Michael P. Mendenhall, Jose Ortiz, Robert W. Pattie Jr., David G. Phillips, John Ramsey, D. J. Salvat, Susan J. Seestrom, E. Shaw, Sky Sjue, Walter E. Sondheim, Brittany Vorndick, Zhehui Wang, Tanner L. Womack, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

The study of neutron cross sections for elements used as efficient “absorbers” of ultracold neutrons (UCN) is crucial for many precision experiments in nuclear and particle physics, cosmology and gravity. In this context, “absorption” includes both the capture and upscattering of neutrons to the energies above the UCN energy region. The available data, especially for hydrogen, do not agree between themselves or with the theory. In this report we describe measurements performed at the Los Alamos National Laboratory UCN facility of the UCN upscattering cross sections for vanadium and for hydrogen in CH2 using simultaneous measurements of the radiative …

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Precision Measurement Of The Neutron Beta-Decay Asymmetry, Michael P. Mendenhall, Robert W. Pattie, Yelena Bagdasarova, David B. Berguno, Leah J. Broussard, Richard Carr, Scott Currie, Xinjian Ding, Bradley W. Filippone, Alejandro Garcia, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Anthony T. Holley, Ran Hong, Takeyasu M. Ito, Andreas Knecht, Chenyu Liu, J. L. Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Dan Melconian, Spencer D. Moore, Christopher L. Morris, Margaret L. Pitt, Blakely Plaster, John C. Ramsey, Roger Rios, Andy Saunders, Susan J. Seestrom, Eduard I. Sharapov, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Andrew R. Young, B. A. Zeck Mar 2013

Precision Measurement Of The Neutron Beta-Decay Asymmetry, Michael P. Mendenhall, Robert W. Pattie, Yelena Bagdasarova, David B. Berguno, Leah J. Broussard, Richard Carr, Scott Currie, Xinjian Ding, Bradley W. Filippone, Alejandro Garcia, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Anthony T. Holley, Ran Hong, Takeyasu M. Ito, Andreas Knecht, Chenyu Liu, J. L. Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Dan Melconian, Spencer D. Moore, Christopher L. Morris, Margaret L. Pitt, Blakely Plaster, John C. Ramsey, Roger Rios, Andy Saunders, Susan J. Seestrom, Eduard I. Sharapov, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Andrew R. Young, B. A. Zeck

Robert W. Pattie Jr.

A new measurement of the neutron β-decay asymmetry A0 has been carried out by the UCNA collaboration using polarized ultracold neutrons (UCN) from the solid deuterium UCN source at the Los Alamos Neutron Science Center (LANSCE). Improvements in the experiment have led to reductions in both statistical and systematic uncertainties leading to A0 = −0.11954(55)stat.(98)syst., corresponding to the ratio of axial-vector to vector coupling λ ≡ gA/gV = −1.2756(30). 

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A High-Field Adiabatic Fast Passage Ultracold Neutron Spin Flipper For The Ucna Experiment, Anthony T. Holley, Leah J. Broussard, J. L. Davis, Kevin Hickerson, Takeyasu M. Ito, Chenyu Liu, J. T. M. Lyles, Mark Makela, Russell R. Mammei, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Roger Rios, Andy Saunders, Andrew R. Young Jun 2012

A High-Field Adiabatic Fast Passage Ultracold Neutron Spin Flipper For The Ucna Experiment, Anthony T. Holley, Leah J. Broussard, J. L. Davis, Kevin Hickerson, Takeyasu M. Ito, Chenyu Liu, J. T. M. Lyles, Mark Makela, Russell R. Mammei, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Roger Rios, Andy Saunders, Andrew R. Young

Robert W. Pattie Jr.

The UCNA collaboration is making a precision measurement of the β asymmetry (A) in free neutron decay using polarized ultracold neutrons (UCN). A critical component of this experiment is an adiabatic fast passage neutron spin flipper capable of efficient operation in ambient magnetic fields on the order of 1 T. The requirement that it operate in a high field necessitated the construction of a free neutron spin flipper based, for the first time, on a birdcage resonator. The design, construction, and initial testing of this spin flipper prior to its use in the first measurement of A with UCN during …

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Measurement Of The Neutron -Asymmetry Parameter A0 With Ultracold Neutrons, Bradley Plaster, R. Rios, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Steven Clayton, Scott Currie, Bradley W. Filippone, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Anthoney T. Holley, Takeyasu M. Ito, Chenyu Liu, Jingyang Liu, Mark Makela, J. W. Martin, Daniel Melconian, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Margaret L. Pitt, John C. Ramsey, R. Russell, Andy Saunders, R. Schmid, Susan J. Seestrom, Sky Sjue, Walter E. Sondheim, E. Tatar, B. Tipton, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Y. P. Xu, H. Yan, Andrew R. Young, J. Yuan Dec 2011

Measurement Of The Neutron -Asymmetry Parameter A0 With Ultracold Neutrons, Bradley Plaster, R. Rios, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Steven Clayton, Scott Currie, Bradley W. Filippone, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Anthoney T. Holley, Takeyasu M. Ito, Chenyu Liu, Jingyang Liu, Mark Makela, J. W. Martin, Daniel Melconian, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, Robert W. Pattie, Margaret L. Pitt, John C. Ramsey, R. Russell, Andy Saunders, R. Schmid, Susan J. Seestrom, Sky Sjue, Walter E. Sondheim, E. Tatar, B. Tipton, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, Y. P. Xu, H. Yan, Andrew R. Young, J. Yuan

Robert W. Pattie Jr.

We present a detailed report of a measurement of the neutron β-asymmetry parameter A0, the parity-violating angular correlation between the neutron spin and the decay electron momentum, performed with polarized ultracold neutrons (UCN). UCN were extracted from a pulsed spallation solid deuterium source and polarized via transport through a 7-T magnetic field. The polarized UCN were then transported through an adiabatic-fast-passage spin-flipper field region, prior to storage in a cylindrical decay volume situated within a 1-T 2 × 2π solenoidal spectrometer. The asymmetry was extracted from measurements of the decay electrons in multiwire proportional chamber and plastic scintillator detector packages …

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Determination Of The Axial-Vector Weak Coupling Constant With Ultracold Neutrons., J. Liu, Michael P. Mendenhall, Anthony T. Holley, Henning O. Back, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Stephen Clayton, Scott Currie, Bradley W. Filippone, A. Garcı́A, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Takeyasu M. Ito, Chenyu Liu, Mark Makela, Russell R. Mammei, J.W. Martin, Daneil Melconian, Charles L. Morris, Robert W. Pattie, A. Pérez Galván, Margaret L. Pitt, Bradley Plaster, John C. Ramsey, R. Rios, R. Russell, Andy Saunders, Susan J. Seestrom, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, H. Yan, Albert R. Young Oct 2010

Determination Of The Axial-Vector Weak Coupling Constant With Ultracold Neutrons., J. Liu, Michael P. Mendenhall, Anthony T. Holley, Henning O. Back, Thomas J. Bowles, Leah J. Broussard, Richard Carr, Stephen Clayton, Scott Currie, Bradley W. Filippone, A. Garcı́A, Peter Geltenbort, Kevin P. Hickerson, J. Todd Hoagland, Gary E. Hogan, B. Hona, Takeyasu M. Ito, Chenyu Liu, Mark Makela, Russell R. Mammei, J.W. Martin, Daneil Melconian, Charles L. Morris, Robert W. Pattie, A. Pérez Galván, Margaret L. Pitt, Bradley Plaster, John C. Ramsey, R. Rios, R. Russell, Andy Saunders, Susan J. Seestrom, Walter E. Sondheim, E. Tatar, Robert B. Vogelaar, Brittany Vorndick, Christopher Wrede, H. Yan, Albert R. Young

Robert W. Pattie Jr.

A precise measurement of the neutron decay β asymmetry A0 has been carried out using polarized ultracold neutrons from the pulsed spallation ultracold neutron source at the Los Alamos Neutron Science Center. Combining data obtained in 2008 and 2009, we report A0=−0.11966±0.00089+0.00123−0.00140, from which we determine the ratio of the axial-vector to vector weak coupling of the nucleon gA/gV=−1.27590+0.00409−0.00445.

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First Measurement Of The Neutron Beta Asymmetry With Ultracold Neutrons, Robert W. Pattie, J. Anaya, Henning O. Back, J. G. Boissevain, Thomas J. Bowles, Leah J. Broussard, Richard Carr, D. J. Clark, Scott Currie, S. Du, Bradley W. Filippone, Peter Geltenbort, A. García, Ayman I. Hawari, Kevin P. Hickerson, R. Hill, M. Hino, S. A. Hoedl, Gary E. Hogan, Anthony T. Holley, Takeyasu M. Ito, T. Kawai, K. Kirch, S. Kitagaki, Steve K. Lamoreaux, Chenyu Liu, Jingyang Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Daniel Melconian, N. Meier, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, A. Pichlmaier, Margaret L. Pitt, Blakely Plaster, John C. Ramsey, Roger Rios, Konstantin Sabourov, A. L. Sallaska, Alexander Saunders, R. Schmid, Susan J. Seestrom, C. Servicky, Sky K. L. Sjue, D. Smith, Walter E. Sondheim, E. Tatar, W. Teasdale, Christopher R. Terai, B. Tipton, M. Utsuro, R. Bruce Vogelaar, Bernard Wehring, Y. P. Xu, Andrew R. Young, J. Yuan Jan 2009

First Measurement Of The Neutron Beta Asymmetry With Ultracold Neutrons, Robert W. Pattie, J. Anaya, Henning O. Back, J. G. Boissevain, Thomas J. Bowles, Leah J. Broussard, Richard Carr, D. J. Clark, Scott Currie, S. Du, Bradley W. Filippone, Peter Geltenbort, A. García, Ayman I. Hawari, Kevin P. Hickerson, R. Hill, M. Hino, S. A. Hoedl, Gary E. Hogan, Anthony T. Holley, Takeyasu M. Ito, T. Kawai, K. Kirch, S. Kitagaki, Steve K. Lamoreaux, Chenyu Liu, Jingyang Liu, Mark Makela, Russell R. Mammei, J. W. Martin, Daniel Melconian, N. Meier, Michael P. Mendenhall, Charles L. Morris, R. Mortensen, A. Pichlmaier, Margaret L. Pitt, Blakely Plaster, John C. Ramsey, Roger Rios, Konstantin Sabourov, A. L. Sallaska, Alexander Saunders, R. Schmid, Susan J. Seestrom, C. Servicky, Sky K. L. Sjue, D. Smith, Walter E. Sondheim, E. Tatar, W. Teasdale, Christopher R. Terai, B. Tipton, M. Utsuro, R. Bruce Vogelaar, Bernard Wehring, Y. P. Xu, Andrew R. Young, J. Yuan

Robert W. Pattie Jr.

We report the first measurement of an angular correlation parameter in neutron #1; decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for #1;30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in …

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