Neutron Beam Effects on Spin Exchange Polarized He-3
Abstract
We have observed depolarization effects when high intensity cold neutron beams are incident on alkali-metal-spin-exchange polarized He-3 cells used as neutron spin filters. This was first observed as a reduction of the maximum attainable He-3 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 LANSCE and ILL. The data reveal a new alkali-metal spin-relaxation mechanism that approximately scales as the square root of the neutron capture-flux density incident on the cell. This is consistent with an effect proportional to the recombination-limited ion concentration, but is much larger than expected from earlier work.
Cite
@article{arxiv.0802.3169,
title = {Neutron Beam Effects on Spin Exchange Polarized He-3},
author = {M. Sharma and E. Babcock and K. H. Andersen and L. Barron-Palos and M. Becker and S. Boag and W. C. Chen and T. E. Chupp and A. Danagoulian and T. R. Gentile and A. Klein and S. Penttila and A. Petoukhov and T. Soldner and E. R. Tardiff and T. G. Walker and W. S. Wilburn},
journal= {arXiv preprint arXiv:0802.3169},
year = {2008}
}
Comments
submitted to Physical Review Letters