Cross sections, angular distributions, and magnetic substate populations in theNa23(n,n′γ)reaction

Abstract

Neutron inelastic scattering cross sections have been determined for six levels in $^{23}\mathrm{Na}$ over the incident neutron energy range 0.52 to 4.23 MeV by measuring the $\ensuremath{\gamma}$-ray production cross sections for 10 deexcitation $\ensuremath{\gamma}$ transitions in the $^{23}\mathrm{Na}(n,{n}^{\ensuremath{'}}\ensuremath{\gamma})$ reaction. $\ensuremath{\gamma}$-ray angular distributions from the first two excited levels were obtained at various incident neutron energies. From these, the magnetic substate populations were evaluated for the 0.440-MeV (${5/2}^{+}$) first excited level and the 2.078-MeV (${7/2}^{+}$) second excited level in $^{23}\mathrm{Na}$. Comparisons have been made between the distributions and magnetic substate populations calculated from compound-nuclear and direct-interaction theory, the former yielding better agreement in the interpretation of experimental results.NUCLEAR REACTIONS $^{23}\mathrm{Na}(n,{n}^{\ensuremath{'}}\ensuremath{\gamma})$, ${E}_{n}=0.52\ensuremath{-}4.23$ MeV; measured $\ensuremath{\sigma}({E}_{n},{\ensuremath{\theta}}_{\ensuremath{\gamma}})$; deduced $\ensuremath{\sigma}({E}_{n})$ and magnetic substate populations; calculated $\ensuremath{\sigma}({E}_{n},{\ensuremath{\theta}}_{\ensuremath{\gamma}})$, $\ensuremath{\sigma}({E}_{n})$, magnetic substate populations; CN and DWBA analysis; natural (Na) target.