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Title: A modular apparatus for use in high-precision measurements of parity violation in polarized eV neutron transmission

Journal Article · · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment
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  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of Kentucky, Lexington, KY (United States)
  2. Indiana Univ., Bloomington, IN (United States)
  3. Univ. Nacional Autónoma de México (Mexico)
  4. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  5. Univ. of Kentucky, Lexington, KY (United States)
  6. Southern Illinois Univ., Carbondale, IL (United States)
  7. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  8. Ohio Univ., Athens, OH (United States)
  9. Berea College, KY (United States)
  10. Univ. of Minnesota Twin Cities, Minneapolis, MN (United States)

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 3He-4He ion chamber neutron flux monitor, two identical cryostats for target cooling, an adiabatic eV-neutron spin flipper, a near-unit efficiency 6Li-7Li scintillation detector operated in current mode, a flexible CAEN data acquisition system, and a neutron spin filter based on spin-exchange optical pumping of 3He 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 139La which employs two identical 139La targets, one to polarize the beam on the p-wave resonance using the weak interaction and one to analyze the polarization.

Research Organization:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Nuclear Physics (NP)
Grant/Contract Number:
89233218CNA000001
OSTI ID:
1828704
Alternate ID(s):
OSTI ID: 1776924
Report Number(s):
LA-UR-19-30409; TRN: US2216306
Journal Information:
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 969; ISSN 0168-9002
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (41)

Parity violation in the compound nucleus journal January 1999
Measurement of the absolute neutron beam polarization from a supermirror polarizer and the absolute efficiency of a neutron spin rotator for the NPDGamma experiment using a polarized  3He neutron spin-filter
  • Musgrave, M. M.; Baeßler, S.; Balascuta, S.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 895 https://doi.org/10.1016/j.nima.2018.03.055
journal July 2018
Angular distribution of γ rays from neutron-induced compound states of La 140 journal March 2018
Parity violation and related effects in neutron-induced reactions journal May 1983
Statistical theory of parity nonconservation in compound nuclei journal October 2000
Measurement of parity-violating γ -ray asymmetry in the capture of polarized cold neutrons on protons journal January 2011
A Measurement of the Nuclear Magnetic Moment of the Helium-3 Atom in Terms of that of the Proton journal January 1993
A liquid parahydrogen target for the measurement of a parity-violating gamma asymmetry in
  • Santra, S.; Barrón Palos, L.; Blessinger, C.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 620, Issue 2-3 https://doi.org/10.1016/j.nima.2010.04.135
journal August 2010
An apparatus and techniques of tests for fundamental symmetries in compound-nucleus scattering with epithermal polarized neutron beams
  • Roberson, N. R.; Bowman, C. D.; Bowman, J. D.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 326, Issue 3 https://doi.org/10.1016/0168-9002(93)90858-F
journal March 1993
Observation of a large parity nonconserving analyzing power in Xe journal June 1996
Neutron polarization with a polarized 3He spin filter
  • Coulter, K. P.; Chupp, T. E.; McDonald, A. B.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 288, Issue 2-3 https://doi.org/10.1016/0168-9002(90)90139-W
journal March 1990
Parity nonconservation in polarized-neutron transmission through La 139 journal November 1991
A large area polarized 3He neutron spin filter
  • Chupp, T. E.; Coulter, K. P.; Kandes, M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 574, Issue 3 https://doi.org/10.1016/j.nima.2007.02.091
journal May 2007
Parity nonconservation in neutron resonances journal April 1983
Isotopic identification of the parity-violating neutron p -wave resonance at energy E 0 = 3.2 eV in Xe journal June 1996
Spin determination of resonance structure in ( U 235 + n ) below 25 keV journal September 1978
Search for time reversal invariance violation in neutron transmission journal December 2014
Ion chamber system for neutron flux measurements
  • Szymanski, J. J.; Bowman, J. D.; Delheij, P. P. J.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 340, Issue 3 https://doi.org/10.1016/0168-9002(94)90139-2
journal March 1994
Parity breaking in the interaction of neutrons with heavy nuclei journal January 1982
Energy and orientation dependence of neutron depolarization in a large single crystal of ferromagnetic holmium journal February 1997
Parity nonconservation for the 0.88-eV neutron resonance in Br 81 journal October 1992
Investigations of parity violation and interference effects in 235U fission induced by resonance neutrons journal January 1999
Physics design of the next-generation spallation neutron target-moderator-reflector-shield assembly at LANSCE
  • Zavorka, Lukas; Mocko, Michael J.; Koehler, Paul E.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 901 https://doi.org/10.1016/j.nima.2018.06.018
journal September 2018
Longitudinal asymmetry and γ-ray angular distribution in neutron-radiative-capture reactions journal February 1993
Effect of Nuclear Collective Motions on S - and P -Wave Strength Functions journal June 1962
Measurements of epithermal neutron depolarization using a polarized rare earth target
  • Alfimenkov, V. P.; Mareev, Yu. D.; Novitsky, V. V.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 352, Issue 3 https://doi.org/10.1016/0168-9002(95)90011-X
journal January 1995
Inelastic collisions between excited alkali atoms and molecules. VII. Sensitized fluorescence and quenching in mixtures of rubidium with H 2 , HD, D 2 , N 2 , CH 4 , CD 4 , C 2 H 4 , and C 2 .H 6 journal November 1970
New observation of space-parity violation in neutron-induced fission of 229Th, 241Pu and 241Am journal January 1994
A spin reversal system for polarized epithermal neutrons
  • Bowman, J. D.; Penttilä, S. I.; Tippens, W. B.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 369, Issue 1 https://doi.org/10.1016/0168-9002(95)00721-0
journal January 1996
Optically polarized He 3 journal December 2017
Parity violation in compound nuclei: experimental methods and recent results journal November 2001
Monte Carlo study of the neutron time emission spectra at the Manuel Lujan Jr. Neutron Scattering Center
  • Mocko, M.; Muhrer, G.; Ino, T.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 594, Issue 3 https://doi.org/10.1016/j.nima.2008.07.034
journal September 2008
Space parity violation in nuclear fission journal October 1989
Parity violation in the 0.734-eV neutron resonance in La 139 journal May 1989
Scintillation detectors for neutron physics research journal June 1979
Measurement of the neutron lifetime by counting trapped protons in a cold neutron beam journal May 2005
Determination of the parahydrogen fraction in a liquid hydrogen target using energy-dependent slow neutron transmission
  • Barrón-Palos, L.; Alarcon, R.; Balascuta, S.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 659, Issue 1 https://doi.org/10.1016/j.nima.2011.07.051
journal December 2011
Investigation of parity violation and interference effects in the angular distributions of fragments originating from 233U fission induced by resonance neutrons journal April 2000
A measurement of the Flight Path 12 cold H2 moderator brightness at LANSCE
  • Seo, P. -N.; Bowman, J. D.; Gericke, M.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 517, Issue 1-3 https://doi.org/10.1016/j.nima.2003.09.048
journal January 2004
Neutron cross sections for He 3 at epithermal energies journal March 2004
Apparatus for parity-violation study via capture γ-ray measurements
  • Seestrom, S. J.; Frankle, C. M.; Bowman, J. D.
  • Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 433, Issue 3 https://doi.org/10.1016/S0168-9002(99)00481-7
journal September 1999