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Title: Comment on 'Effect of a polarized hydrogen target on the polarization of a stored proton beam'

Abstract

Meyer [Phys. Rev. E 50, 1485 (1994)] analyzed the filtering mechanism of polarizing a stored beam by scattering from an internal polarized target. We noticed in Meyer's derivation of Eq. (4) of that paper that he had added a new twist to an old argument [W. Brueckner et al., Physics with Antiprotons at LEAR in the ACOL Era: Proceedings of the Third LEAR Workshop, Tignes, Savoie, France, January 19-26, 1985 (Editions Frontieres, Gif-sur-Yvette, France, 1985), p. 245] by allowing some particles that are spin flipped to be kept in the beam. We show that this invalidates the old result and leads to a more complicated expression for the buildup of polarization.

Authors:
;  [1]
  1. Brookhaven National Laboratory, Upton, New York 11973 (United States)
Publication Date:
OSTI Identifier:
20778715
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics; Journal Volume: 73; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevE.73.028501; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 43 PARTICLE ACCELERATORS; HYDROGEN; POLARIZATION; POLARIZED TARGETS; PROTON BEAMS; PROTON-NUCLEON INTERACTIONS; SCATTERING; SPIN FLIP

Citation Formats

MacKay, W.W., and Montag, C. Comment on 'Effect of a polarized hydrogen target on the polarization of a stored proton beam'. United States: N. p., 2006. Web. doi:10.1103/PHYSREVE.73.0.
MacKay, W.W., & Montag, C. Comment on 'Effect of a polarized hydrogen target on the polarization of a stored proton beam'. United States. doi:10.1103/PHYSREVE.73.0.
MacKay, W.W., and Montag, C. Wed . "Comment on 'Effect of a polarized hydrogen target on the polarization of a stored proton beam'". United States. doi:10.1103/PHYSREVE.73.0.
@article{osti_20778715,
title = {Comment on 'Effect of a polarized hydrogen target on the polarization of a stored proton beam'},
author = {MacKay, W.W. and Montag, C.},
abstractNote = {Meyer [Phys. Rev. E 50, 1485 (1994)] analyzed the filtering mechanism of polarizing a stored beam by scattering from an internal polarized target. We noticed in Meyer's derivation of Eq. (4) of that paper that he had added a new twist to an old argument [W. Brueckner et al., Physics with Antiprotons at LEAR in the ACOL Era: Proceedings of the Third LEAR Workshop, Tignes, Savoie, France, January 19-26, 1985 (Editions Frontieres, Gif-sur-Yvette, France, 1985), p. 245] by allowing some particles that are spin flipped to be kept in the beam. We show that this invalidates the old result and leads to a more complicated expression for the buildup of polarization.},
doi = {10.1103/PHYSREVE.73.0},
journal = {Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics},
number = 2,
volume = 73,
place = {United States},
year = {Wed Feb 15 00:00:00 EST 2006},
month = {Wed Feb 15 00:00:00 EST 2006}
}
  • We investigate the change of polarization of a stored proton beam induced by the presence of an internal, polarized, atomic hydrogen target. Three distinct mechanisms are identified that significantly contribute to the beam polarization. The calculated polarization rate agrees with the result of a recent experiment.
  • We report experimental results of a stored proton beam polarized by sp dependent attenuation through a high density polarized hydrogen target. The experiment was carried out at the Heidelberg low energy Test Storage Ring. The polarized hydrogen storage cell gas target consisted of polarized hydrogen atoms produced by the Heidelberg atomic beam source injected into a thin walled, cylindrical aluminum tube. (AIP) {copyright} {ital 1996 American Institute of Physics.} {copyright} {ital 1995 American Institute of Physics.}
  • The polarization buildup in a p-bar beam due to the interaction of stored antiprotons with polarized protons of a hydrogen target is considered. The corresponding cross section is calculated in the energy interval 20<T{sub lab}<100 MeV using the Paris nucleon-antinucleon optical potential. It follows from this estimate that, at realistic parameters of a storage ring and a target, the filtering mechanism can provide a noticeable polarization in a time comparable with the beam lifetime.
  • Targets for scattering experiments, composed of polarized nuclei (particularly protons), are considered. Desirable proton target criteria, such as the magnitude of the polarization, the effects of the beam on the polarization, the characteristics of the matrix in which the protons are to be located, etc., are reviewed. Within the framework of these criteria, static and dynamic methods for obtaining polarized targets are evaluated. A method utilizing the solid effect'' is found to be promising. In the solid effect, a microwave magnetic field is applied to a target containing paramagnetic centers, and the nuclei are polarized through spin-flip processes. A targetmore » consisting of radiation-damaged polythene is described. (T.F.H.)« less