Scattering of 7.8-MeV Polarized Neutrons fromHe4and the Phase Shifts Below 8 MeV

The polarization analyzing power for the elastic scattering of 7.80- and 3.38-MeV neutrons from ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ has been measured at laboratory angles ranging from 40 to 140°. Polarized neutrons were produced in the ${}_{}{}^9{}_{}{}^{}\mathrm{Be}(\alpha ,n){}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ reaction at 45° (lab) with a mean $\alpha$ energy of 2.55 MeV. Results of a phase-shift analysis are given and are found to agree with optical-model calculations reported by Satchler et al.