Interaction Of 380 Kev Polarized Neutrons With Complex Nuclei

Measurements of the polarization produced in the scattering of neutrons from heavy nuclei have been carried out at neutron energies of 380 and 980 kev. The Li/sup 7/(p, n)Be/sup 7/ reaction was used as a source of polarized neutrons. Right-left asymmetries in scattering of these neutrons from several elements ranging in atomic weight from 55 to 238 were measured at scattering angles of 55, 90, and 130 deg . With few exceptions the observed polarizations vary smoothly with atomic weight. Measured values of the polarization range from -0.11 to plus or minus 0.15 at 380 kev, and from --0.17 to plus or minus 0.20 at 980 kev. The results at 380-kev neutron energy are compared with values predicted by the complex square well potential modified by a surface spin-orbit interaction. Using several sets of well parameters it has not been possible to reproduce the experimental results. (auth).