Determination of the parahydrogen fraction in a liquid hydrogen target using energy-dependent slow neutron transmission
Por:
Barrón-Palos L., Alarcon R., Balascuta S., Blessinger C., Bowman J.D., Chupp T.E., Covrig S., Crawford C.B., Dabaghyan M., Dadras J., Dawkins M., Fox W., Gericke M.T., Gillis R.C., Lauss B., Leuschner M.B., Lozowski B., Mahurin R., Mason M., Mei J., Nann H., Penttilä S.I., Ramsay W.D., Salas-Bacci A., Santra S., Seo, PN, Sharma M., Smith T., Snow W.M., Wilburn W.S., Yuan V.
Publicada:
11 dic 2011
Resumen:
The NPDGamma collaboration is performing a measurement of the very small parity-violating asymmetry in the angular distribution of the 2.2 MeV gamma-rays from the capture of polarized cold neutrons on protons (A(gamma)) The estimated size of A(gamma) is 5 x 10(-8), and the measured asymmetry is proportional to the neutron polarization upon capture. Since the interaction of polarized neutrons with one of the two hydrogen molecular states (orthohydrogen) can lead to neutron spin-flip scattering, it is essential that the hydrogen in the target is mostly in the molecular state that will not depolarize the neutrons (>= 99.8% parahydrogen). For that purpose, in the first stage of the NPDGamma experiment at the Los Alamos Neutron Science Center (LANSCE), we operated a 16-1 liquid hydrogen target, which was filled in two different occasions. The parahydrogen fraction in the target was accurately determined in situ by relative neutron transmission measurements. The result of these measurements
Filiaciones:
Barrón-Palos L.:
Arizona State University, Tempe, AZ 85287, United States
Universidad Nacional Autónoma de México, México, DF 04510, Mexico
Alarcon R.:
Arizona State University, Tempe, AZ 85287, United States
Balascuta S.:
Arizona State University, Tempe, AZ 85287, United States
Blessinger C.:
Indiana University, Bloomington, IN 47405, United States
Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
Bowman J.D.:
Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
Chupp T.E.:
University of Michigan, Ann Arbor, MI 48104, United States
Covrig S.:
University of New Hampshire, Durham, NH 03824, United States
Thomas Jeffers on National Accelerator Facility, Newport News, VA 23606, United States
Crawford C.B.:
University of Tennessee, Knoxville, TN 37996, United States
University of Kentucky, Lexington, KY 40506, United States
Dabaghyan M.:
University of New Hampshire, Durham, NH 03824, United States
Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States
Dadras J.:
University of Tennessee, Knoxville, TN 37996, United States
Dawkins M.:
Indiana University, Bloomington, IN 47405, United States
Texas A and M University, College Station, TX 77843, United States
Fox W.:
Indiana University, Bloomington, IN 47405, United States
Gericke M.T.:
Thomas Jefferson National Accelerator Facility, Newport News, VA 23606, United States
University of Manitoba, Winnipeg, MB R3T2N2, Canada
Gillis R.C.:
Arizona State University, Tempe, AZ 85287, United States
University of Manitoba, Winnipeg, MB R3T 2N2, Canada
Lauss B.:
University of California, Berkeley, CA 94720, United States
Paul Scherrer Institut, CH-5232 Villigen-PSI, Switzerland
Leuschner M.B.:
Indiana University, Bloomington, IN 47405, United States
Procure, Bloomington, IN 47408, United States
Lozowski B.:
Indiana University, Bloomington, IN 47405, United States
Mahurin R.:
University of Tennessee, Knoxville, TN 37996, United States
Mason M.:
University of New Hampshire, Durham, NH 03824, United States
Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, United States
Mei J.:
Indiana University, Bloomington, IN 47405, United States
Nann H.:
Indiana University, Bloomington, IN 47405, United States
Penttilä S.I.:
Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States
Ramsay W.D.:
TRIUMF, Vancouver, BC V6T 2A3, Canada
Salas-Bacci A.:
Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Santra S.:
Indiana University, Bloomington, IN 47405, United States
Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
Sharma M.:
University of Michigan, Ann Arbor, MI 48104, United States
Smith T.:
University of Dayton, Dayton, OH 45469, United States
Snow W.M.:
Indiana University, Bloomington, IN 47405, United States
Wilburn W.S.:
Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Yuan V.:
Los Alamos National Laboratory, Los Alamos, NM 87545, United States
Duke University, Durham, NC 27708, United States
North Carolina State University, Raleigh, NC 27695, United States
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