Slow-Neutron Scattering Cross Sections of Terbium, Ytterbium, and Lutetium

Abstract

The coherent neutron scattering cross sections of terbium, ytterbium, and lutetium as determined from the neutron diffraction measurements on Tb${\mathrm{C}}_2$, Yb${\mathrm{C}}_2$, Yb, and Lu metals are found to be 7.2±0.4, 20.0±0.4, and 6.70±0.37 barns, respectively, all with amplitude of positive phase. The total scattering cross sections of Tb, Yb, and Lu and the magnetic scattering cross sections of ${\mathrm{Tb}}^{+3\mathrm{}}$ and ${\mathrm{Yb}}^{+3\mathrm{}}$ are evaluated for thermal neutron energies. The neutron diffraction data also show the Debye temperatures of Yb and Lu metals to be 109±5°K and 161±7°K, respectively.