A modular apparatus for use in high-precision measurements of parity violation in polarized eV neutron transmission`
| Autor: | Schaper, D. C., Auton, C., Barrón-Palos, L., Borrego, M., Chavez, A., Cole, L., Crawford, C. B., Curole, J., Dhahri, H., Dickerson, K. A., Doskow, J., Fox, W., Gervais, M. H., Goodson, B. M., Knickerbocker, K., Jiang, C., King, P. M., Lu, H., Mocko, M., Olivera-Velarde, D., Munoz, J. G. Otero, Penttilä, S. I., Pérez-Martín, A., Snow, W. M., Steffen, K., Vanderwerp, J., Visser, G. |
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| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1016/j.nima.2020.163961 |
| Popis: | We describe a modular apparatus for use in parity-violation measurements in epithermal neutron-nucleus resonances with high instantaneous neutron fluxes at the Manuel Lujan Jr.\ Neutron Scattering Center at Los Alamos National Laboratory. This apparatus is designed to conduct high-precision measurements of the parity-odd transmission asymmetry of longitudinally polarized neutrons through targets containing nuclei with p-wave neutron-nucleus resonances in the 0.1-10 eV energy regime and to accommodate a future search for time reversal violation in polarized neutron transmission through polarized nuclear targets. The apparatus consists of an adjustable neutron and gamma collimation system, a \(^3\)He-$^{4}$He ion chamber neutron flux monitor, two identical cryostats for target cooling, an adiabatic eV-neutron spin flipper, a near-unit efficiency \(^6\)Li-\(^{7}\)Li scintillation detector operated in current mode, a flexible CAEN data acquisition system, and a neutron spin filter based on spin-exchange optical pumping of $^{3}$He gas. We describe the features of the apparatus design devoted to the suppression of systematic errors in parity-odd asymmetry measurements. We describe the configuration of the apparatus used to conduct a precision measurement of parity violation at the 0.7 eV p-wave resonance in $^{139}$La which employs two identical $^{139}$La targets, one to polarize the beam on the p-wave resonance using the weak interaction and one to analyze the polarization. Comment: 43 pages, 23 figures |
| Databáze: | arXiv |
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