Neutron-Proton Polarization Measurements at 14.2 MeV

Abstract

The magnitude of the polarization observed in neutron-proton scattering for E_n < 20 MeV is known to be less than a few percent and has been difficult to measure accurately. The usual experimental arrangement used to obtain n-p polarization data involves organic scintillators as scatterers; consequently, the systematic accuracy depends on the amount of multiple scattering from carbon and hydrogen in the scatterer. Although n-¹²C scattering yields large polarization in the relevant energy region¹⁾, the background polarization has been either assumed to be zero or, in one instance at 23.1 MeV²⁾, demonstrated to be small by measurements with two scatteres of different size.

Work supported in part by U.S. Energy Research and Development Administration.