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Article: Precision neutron polarimetry for neutron beta decay.
- Article from:
- Journal of Research of the National Institute of Standards and Technology
- Article date:
- May 1, 2005
- Author:
CopyrightCOPYRIGHT 2005 National Institute of Standards and Technology. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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The abBA collaboration is developing a new type of field-expansion spectrometer for a measurement of the three correlation coefficients a, A, and B and the shape parameter b. The measurement of A and B requires precision neutron polarimetry. We will polarize a pulsed cold neutron beam from the SNS using a [.sup.3]He neutron spin filter. The well-known polarizing cross section for n-[.sup.3]He has a 1/v dependence, where v is the neutron velocity, which is used to determine the absolute beam polarization through a time-of-flight (TOF) measurement. We show that by measuring the TOF dependence of A and B, the coefficients and the neutron polarization can be determined with a ...