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Emit: An Apparatus To Test Time Reversal Invariance In Polarized Neutron Decay, H. P. Mumm, A. Garcia, L. Grout, M. Howe, L. P. Parazzoli, R. G. H. Robertson, K. M. Sundqvist, J. F. Wilkerson, S. J. Freedman, B. K. Fujikawa, L. J. Lising, M. S. Dewey, J. S. Nico, A. K. Thompson, T. E. Chupp, R. L. Cooper, K. P. Coulter, S. R. Hwang, R. C. Welsh, L. J. Broussard, C. A. Trull, F. E. Wietfeldt, Gordon L. Jones
Emit: An Apparatus To Test Time Reversal Invariance In Polarized Neutron Decay, H. P. Mumm, A. Garcia, L. Grout, M. Howe, L. P. Parazzoli, R. G. H. Robertson, K. M. Sundqvist, J. F. Wilkerson, S. J. Freedman, B. K. Fujikawa, L. J. Lising, M. S. Dewey, J. S. Nico, A. K. Thompson, T. E. Chupp, R. L. Cooper, K. P. Coulter, S. R. Hwang, R. C. Welsh, L. J. Broussard, C. A. Trull, F. E. Wietfeldt, Gordon L. Jones
Articles
We describe an apparatus used to measure the triple-correlation term (D (σ) over cap (n).p(e)xp(nu)) in the beta decay of polarized neutrons. The D coefficient is sensitive to possible violations of time reversal invariance. The detector has an octagonal symmetry that optimizes electron-proton coincidence rates and reduces systematic effects. A beam of longitudinally polarized cold neutrons passes through the detector chamber, where a small fraction undergo beta decay. The final-state protons are accelerated and focused onto arrays of cooled semiconductor diodes, while the coincident electrons are detected using panels of plastic scintillator. Details regarding the design and performance of the …
Neutron Cross Sections For He-3 At Epithermal Energies, C. D. Keith, Z. Chowdhuri, D. R. Rich, W. M. Snow, J. D. Bowman, S. L. Penttila, D. A. Smith, M. B. Leuschner, V. R. Pomeroy, Gordon L. Jones, E. I. Sharapov
Neutron Cross Sections For He-3 At Epithermal Energies, C. D. Keith, Z. Chowdhuri, D. R. Rich, W. M. Snow, J. D. Bowman, S. L. Penttila, D. A. Smith, M. B. Leuschner, V. R. Pomeroy, Gordon L. Jones, E. I. Sharapov
Articles
High accuracy, absolute measurements of the neutron total cross section for He-3 are reported for incident neutron energies 0.1-400 eV. The measurements were performed at the LANSCE short-pulse neutron spallation source. Using the previously determined cross section for neutron elastic scattering, 3.367+/-0.019 b, we extract a new value for the energy dependence of the He-3(n,p)He-3 reaction cross section, sigma(np)=(849.77+/-0.14+/-1.02)E-1/2-(1.253+/-0.00+/-(+0.008)(-0.049))b, where the neutron energy is expressed in eV. The first uncertainty is statistical, the second systematic.