Published August 22, 2008 | Version v1
Journal article

Neutron Beam Effects on Spin-Exchange-Polarized 3He

  • 1. FOCUS Center and Physics Department, University of Michigan, Ann Arbor, Michigan 48104 (United States)
  • 2. Institut Laue-Langevin, BP 156, 38042 Grenoble Cedex 9 (France)
  • 3. Universidad Nacional Autonoma de Mexico, Mexico, D.F. 04510 (Mexico)
  • 4. Arizona State University, Tempe, Arizona 85287 (United States)
  • 5. Physikalisches Institut, Universitaet Heidelberg, Philosophenweg 12, 69120 Heidelberg (Germany)
  • 6. ISIS, Rutherford Appleton Labs, Chilton, Didcot OX11 0QX (United Kingdom)
  • 7. National Institute of Standard and Technology, Gaithersburg, Maryland 20899-8461 (United States)
  • 8. Los Alamos National Lab, Los Alamos, New Mexico 87545 (United States)
  • 9. Oak Ridge National Lab, Oak Ridge, Tennessee 37831 (United States)
  • 10. University of Wisconsin, Madison, Wisconsin 53706 (United States)

Description

We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal spin-exchange-polarized 3He cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable 3He polarization and was attributed to a decrease of alkali-metal polarization, which led us to directly measure alkali-metal polarization and spin relaxation over a range of neutron fluxes at Los Alamos Neutron Science Center and Institute Laue-Langevin. The data reveal a new alkali-metal spin-relaxation mechanism that approximately scales as √(φn), where φn is the neutron capture-flux density incident on the cell. This is consistent with an effect proportional to the concentration of electron-ion pairs but is much larger than expected from earlier work

Additional details

Publishing Information

Journal Title
Physical Review Letters
Journal Volume
101
Journal Issue
8
Journal Page Range
p. 083002-083002.5
ISSN
0031-9007
CODEN
PRLTAO

Optional Information

Notes
(c) 2008 The American Physical Society