Neutron-proton polarization measurements near 20-MeV incident neutron energy

Using the ${}_{}{}^3{}_{}{}^{}\mathrm{H}(d,\overrightarrow{n}){}_{}{}^4{}_{}{}^{}\mathrm{He}$ reaction as a source of polarized neutrons, measurements of the $n-p$ polarizations have been made at 16.9 and 21.1 MeV. Results are reported at 40, 60, 80, and 140° c.m. for both energies as well as at 100 and 120° c.m. for 21.1 MeV. Comparisons are made with predictions of the LRL-X and the YALE-IV phase-shift analysis. The data favor the LRL-X analysis at forward angles and the YALE-IV analysis at backward angles.