Publications [#246684] of Calvin R. Howell

Papers Published
  1. Weisel, GJ; Tornow, W; Crowe, BJ; Crowell, AS; Esterline, JH; Howell, CR; Kelley, JH; Macri, RA; Pedroni, RS; Walter, RL; Witała, H, Neutron-deuteron analyzing power data at 19.0 MeV, Physical Review C - Nuclear Physics, vol. 81 no. 2 (February, 2010), pp. 024003, American Physical Society (APS) [repository], [doi] .

    Abstract:
    Measurements of neutron-deuteron (n-d) analyzing power Ay(θ) at En=19.0 MeV are reported at 16 angles from θc.m.=46.7 to 152.0°. The objective of the experiment is to better characterize the discrepancies between n-d data and the predictions of three-nucleon calculations for neutron energies above 16.0 MeV. The experiment used a shielded neutron source, which produced polarized neutrons via the H2(d-,n-)He3 reaction, a deuterated liquid scintillator center detector (CD) and liquid-scintillator neutron side detectors. A coincidence between the CD and the side detectors isolated the elastic-scattering events. The CD pulse height spectrum associated with each side detector was sorted by using pulse-shape discrimination, time-of-flight techniques, and by removing accidental coincidences. A Monte Carlo computer simulation of the experiment accounted for effects due to finite geometry, multiple scattering, and CD edge effects. The resulting high-precision data (with absolute uncertainties ranging from 0.0022 to 0.0132) have a somewhat lower discrepancy with the predictions of three-body calculations, as compared to those found at lower energies. © 2010 The American Physical Society.

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