A measurement of parity-violating gamma-ray asymmetries in polarized cold neutron capture on Cl-35, Cd-113, and La-139
Type of Work
Nuclear Instruments & Methods in Physics Research Section A-Accelerators Spectrometers Detectors and Associated Equipment
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 He-3 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 Cl-35, Cd-113, and La-139 targets. Upper limits on the parity-allowed asymmetry s(n) (.) (k(gamma) x k(n)) were set at the level of 7 x 10(-6) for all three targets. Parity-violating asymmetries S-n (.) k(gamma) were observed in Cl-35, A(gamma) = (-29.1 +/- 6.7) x 10(-6), and La-139, A(gamma) = (-15.5 +/- 7.1) x 10(-6), values consistent with previous measurements. (C) 2003 Elsevier B.V. All rights reserved.
Mitchell, G. S.; Blessinger, C. S.; Bowman, J. D.; Chupp, T. E.; Coulter, K. P.; Gericke, M.; Jones, Gordon L.; Leuschner, M. B.; Nann, H.; Page, S. A.; Penttila, S. I.; Smith, T. B.; Snow, W. M.; and Wilburn, W. S., "A measurement of parity-violating gamma-ray asymmetries in polarized cold neutron capture on Cl-35, Cd-113, and La-139" (2004). Hamilton Digital Commons.
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