Browsing by Author "Ding, X."

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    A new method for measuring the neutron lifetime using an in situ neutron detector
    Morris, C. L.; Adamek, E. R.; Broussard, L. J.; Callahan, N. B.; Clayton, S. M.; Cude-Woods, C.; Currie, S. A.; Ding, X.; Fox, W.; Hickerson, K. P.; Hoffbauer, M. A.; Holley, A. T.; Komives, A.; Liu, C. Y.; Makela, M.; Pattie, R. W., Jr.; Ramsey, J.; Salvat, D. J.; Saunders, A.; Seestrom, S. J.; Sharapov, E. I.; Sjue, S. K.; Tang, Z.; Vanderwerp, J.; Vogelaar, R. Bruce; Walstrom, P. L.; Wang, Z.; Wei, Wanchun; Wexler, J. W.; Womack, T. L.; Young, A. R.; Zeck, B. A. (2017-05)
    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. (C) 2017 Author(s).
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    Precision measurement of the neutron beta-decay asymmetry
    Mendenhall, M. P.; Pattie, R. W.; Bagdasarova, Y.; Berguno, D. B.; Broussard, L. J.; Carr, Rachel E.; Currie, S.; Ding, X.; Filippone, B. W.; Garcia, A.; Geltenbort, P.; Hickerson, K. P.; Hoagland, J.; Holley, A. T.; Hong, R.; Ito, T. M.; Knecht, A.; Liu, C. Y.; Liu, J. L.; Makela, M.; Mammei, R. R.; Martin, J. W.; Melconian, D.; Moore, S. D.; Morris, C. L.; Galvan, A. P.; Picker, R.; Pitt, M. L.; Plaster, B.; Ramsey, J. C.; Rios, R.; Saunders, A.; Seestrom, S. J.; Sharapov, E. I.; Sondheim, W. E.; Tatar, E.; Vogelaar, R. Bruce; VornDick, B.; Wrede, C.; Young, A. R.; Zeck, B. A.; Ucna Collaboration (American Physical Society, 2013-03-25)
    A new measurement of the neutron beta-decay asymmetry A(0) has been carried out by the UCNA Collaboration using polarized ultracold neutrons (UCNs) from the solid deuterium UCN source at the Los Alamos Neutron Science Center. Improvements in the experiment have led to reductions in both statistical and systematic uncertainties leading to A(0) = -0.11954(55)(stat)(98)(syst), corresponding to the ratio of axial-vector to vector coupling lambda = g(A)/g(V) = -1.2756(30).