Theoretical Evaluation of Neutron-nucleus Scattering Parameters from Experimental Data in the 6 ≤ A ≤ 60 Mass Region

Abstract

Systematic calculations of the neutron-nucleus scattering parameters at several neutron energies Ei < 2 keV have been performed for 37 isotopes (⁶Li,... ⁵⁹Co) in the mass region of 6 ≤ A ≤ 60, using the large compilation of experimental neutron-nucleus scattering data obtained in Garching. In the first stage of these calculations, the s-wave potential scattering radius R’, the scattering lengths b_coh, b_±, and the bound state parameters (E_b, Γ_γ , gΓ⁰_n) have been calculated for each isotope, employing the general least squares fit (GLSQF) for the experimental and the corresponding theoretical values of the total neutron-nucleus cross sections σ^exp_tot(E_i) at several energies E_i, absorption cross sections σ_abs(E_o) and of the coherent scattering lengths b_coh. The theoretical expressions for these parameters were deduced on the basis of the usual S-matrix formalism with no assumption about the particular shape of the optical model potential. In the second stage of our calculations, the spherical Fiedeldey- Frahn optical potential was employed for the pure theoretical description or the above mentioned neutron-nucleus scattering characteristics. The results obtained have been analyzed and compared with the values deduced from measurements.