Neutron analysing powers and a low-energy optical model analysis
J R M Annand; R B Galloway; J R M Annand; Dept. of Phys., Edinburgh Univ., UK; R B Galloway; Dept. of Phys., Edinburgh Univ., UK
Журнал:
Journal of Physics G: Nuclear Physics
Дата:
1985-12-01
Аннотация:
Neutron elastic scattering analysing powers have been measured at 3 MeV incident energy for <sup>nat</sup>W, <sup>nat</sup>Hg, <sup>nat</sup>Tl, <sup>nat</sup>Pb, <sup>209</sup>Bi and <sup>238</sup>U. Differential cross sections have also been measured for <sup>nat</sup>Hg, <sup>nat</sup>Tl, <sup>nat</sup>Pb and <sup>208</sup>Bi. A local, phenomenological, spherical optical model analysis of these data is performed with comparison made between pure Woods-Saxon real form factors and those having surface-peaked components. The latter have been predicted in dispersion integral calculations. The effects of introducing an imaginary spin-orbit potential component are also tested. For <sup>nat</sup>W and <sup>238</sup>U a deformed phenomenological optical potential is used in coupled-channels calculations. Coupled-channels effects are also investigated for <sup>208</sup>Pb, assuming it to be a harmonic vibrator. Microscopic calculations of real and imaginary potentials are made using the methods of Brieva and Rook, (1977,8), and Jeukenne et al. (1977). Calculation of the spin-orbit interaction is less sophisticated with an energy- and density-independent form used. At 3 MeV compound elastic scattering must be accounted for in all nuclei presently studied. This has been calculated using a recent formulation of the statistical model.
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