A measurement of parity-violating gamma-ray asymmetries in polarized cold neutron capture on 35Cl, 113Cd, and 139La

G. S. Mitchell; C. S. Blessinger; J. D. Bowman; T. E. Chupp; K. P. Coulter; M. T. W. Gericke; G. L. Jones; M. B. Leuschner; H. Nann; S. A. Page; S. I. Penttila; T. B. Smith; W. M. Snow; W. S. Wilburn

doi:10.1016/j.nima.2003.11.192

arXiv · nucl-ex/0401009

A measurement of parity-violating gamma-ray asymmetries in polarized cold neutron capture on 35Cl, 113Cd, and 139La

G. S. Mitchell·C. S. Blessinger·J. D. Bowman·T. E. Chupp·K. P. Coulter·M. T. W. Gericke·G. L. Jones·M. B. Leuschner·H. Nann·S. A. Page·S. I. Penttila·T. B. Smith·W. M. Snow·W. S. Wilburn

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Abstract

An apparatus for measuring parity-violating asymmetries in gamma-ray emission following polarized cold neutron capture was constructed as a 1/10th scale test of the design for the forthcoming n+p->d+gamma experiment at LANSCE. The elements of the polarized neutron beam, including a polarized 3He neutron spin filter and a radio frequency neutron spin rotator, are described. Using CsI(Tl) detectors and photodiode current mode readout, measurements were made of asymmetries in gamma-ray emission following neutron capture on 35Cl, 113Cd, and 139La targets. Upper limits on the parity-allowed asymmetry $s_n \cdot (k_γ \times k_n)$ were set at the level of 7 x 10^-6 for all three targets. Parity-violating asymmetries $s_n \cdot k_γ$ were observed in 35Cl, A_gamma = (-29.1 +- 6.7) x 10^-6, and 139La, A_gamma = (-15.5 +- 7.1) x 10^-6, values consistent with previous measurements.

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G. S. Mitchell, C. S. Blessinger, J. D. Bowman, T. E. Chupp, K. P. Coulter, M. T. W. Gericke, G. L. Jones, M. B. Leuschner, H. Nann, S. A. Page, S. I. Penttila, T. B. Smith, W. M. Snow, W. S. Wilburn. 2004-01-08. A measurement of parity-violating gamma-ray asymmetries in polarized cold neutron capture on 35Cl, 113Cd, and 139La. https://doi.org/10.1016/j.nima.2003.11.192

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