High-efficiency resonant rf spin rotator with broad phase space acceptance for pulsed polarized cold neutron beams

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Authors

P. N. Seo, Los Alamos National Laboratory
L. Barron-Palos, Arizona State University at the Tempe Campus
J. D. Bowman, Los Alamos National Laboratory
T. E. Chupp, University of Michigan - Ann Arbor
C Crawford, University of Tennessee - Knoxville
M. Dabaghyan, University of New Hampshire
M. Dawkins, Indiana University - Bloomington
S. J. Freedman, University of California - Berkeley
T. Gentile, National Institute of Standards and Technology
M. T. Gericke, University of Manitoba
R. C. Gillis, University of Manitoba
G. L. Greene, Oak Ridge National LaboratoryFollow
F. William Hersman, University of New HampshireFollow
G. L. Jones, Hamilton College - Clinton
M. Kandes, University of Michigan - Ann Arbor
S. Lamoreaux, Los Alamos National Laboratory
B. Lauss, University of California - Berkeley
M. B. Lueschner, Indiana University - Bloomington
R. Mahurin, University of Tennessee - KnoxvilleFollow
M. Mason, University of New Hampshire
J. Mei, Indiana University - Bloomington
G. S. Mitchell, Los Alamos National Laboratory
H. Nann, Indiana University - Bloomington
S. A. Page, University of Manitoba
S. I. Penttila, Los Alamos National Laboratory
W. D. Ramsay, University of Manitoba
A. Salas Bacci, Los Alamos National Laboratory
S. Santra, Indiana University - Bloomington
M. Sharma, University of Michigan - Ann Arbor
T. B. Smith, University of Dayton
W. M. Snow, Indiana University - Bloomington
W. S. Wilburn, Los Alamos National Laboratory
H. Zhu, University of New Hampshire

Abstract

High precision fundamental neutron physics experiments have been proposed for the intense pulsed spallation neutron beams at JSNS, LANSCE, and SNS to test the standard model and search for new physics. Certain systematic effects in some of these experiments have to be controlled at the few ppb level. The NPDGamma experiment, a search for the small parity-violating gamma-ray asymmetry A(gamma) in polarized cold neutron capture on parahydrogen, is one example. For the NPDGamma experiment we developed a radio-frequency resonant spin rotator to reverse the neutron polarization in a 9.5 cm x 9.5 cm pulsed cold neutron beam with high efficiency over a broad cold neutron energy range. The effect of the spin reversal by the rotator on the neutron beam phase space is compared qualitatively to rf neutron spin flippers based on adiabatic fast passage. We discuss the design of the spin rotator and describe two types of transmission-based neutron spin-flip efficiency measurements where the neutron beam was both polarized and analyzed by optically polarized (3)He neutron spin filters. The efficiency of the spin rotator was measured at LANSCE to be 98.8 +/- 0.5% for neutron energies from 3 to 20 meV over the full phase space of the beam. Systematic effects that the rf spin rotator introduces to the NPDGamma experiment are considered.

Department

Physics

Publication Date

8-6-2008

Journal Title

Physical Review Special Topics - Accelerators and Beams

Publisher

The Americal Physical Society

Digital Object Identifier (DOI)

10.1103/PhysRevSTAB.11.084701

Document Type

Article

Recommended Citation

Seo, P. N.; Barron-Palos, L.; Bowman, J. D.; Chupp, T. E.; Crawford, C; Dabaghyan, M.; Dawkins, M.; Freedman, S. J.; Gentile, T.; Gericke, M. T.; Gillis, R. C.; Greene, G. L.; Hersman, F. William; Jones, G. L.; Kandes, M.; Lamoreaux, S.; Lauss, B.; Lueschner, M. B.; Mahurin, R.; Mason, M.; Mei, J.; Mitchell, G. S.; Nann, H.; Page, S. A.; Penttila, S. I.; Ramsay, W. D.; Bacci, A. Salas; Santra, S.; Sharma, M.; Smith, T. B.; Snow, W. M.; Wilburn, W. S.; and Zhu, H., "High-efficiency resonant rf spin rotator with broad phase space acceptance for pulsed polarized cold neutron beams" (2008). Physical Review Special Topics - Accelerators and Beams. 1.
https://scholars.unh.edu/physics_facpub/1

Rights

This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.