POLARIMETERS FOR MEDIUM-ENERGY NEUTRONS

Polarimeters for medium-energy neutrons are described which are based on the fact that scattering of polarized neutrons from unpolarized hydrogen nuclei exhibits a left-right (or an up-down ) asymmetry. Configurations are described for neutron polarimeters that use the analyzing power of neutron-proton scattering from the hydrogen in an organic scintillator material. The scattering angle θ and the azimuthal (out-of-plane) angle φ for the neutron-proton scattering event are determined from the position of the interaction in each of the two detectors involved in a given event. Consideration is given to V-configuration polarimeters, an axial-configuration polarimeter for use with a solid-angle-limiting aperture of a neutron spin-rotation magnet between the target and the polarimeter, and polarimeters configured with parallel planes of scintillator material.