Total Neutron Cross Sections of Magnesium, Aluminum, Silicon, Zirconium, Niobium and Molybdenum in Energy Range from 0.001 to 0.3 eV

Abstract

Total neutron cross sections of Mg, Al, Si, Zr, Nb and Mo at room temperature have been measured in the energy range of 0.001–0.3 eV using a chopper and TOF facility of the Musashi Institute of Technology Research Reactor. The experiments were performed for solid and powdered samples. For these samples inelastic and elastic scattering cross sections were respectively calculated with the THRUSH code assuming Debye-type frequency spectrum and with the UNCLE-TOM code using crystal structure and lattice constants of each sample. For solid samples the measured cross sections agreed well with the calculations below the Bragg cut-off energies. For the powdered samples there were good agreements above the Bragg cut-off, and the measurements were larger than the calculations below the Bragg cut-off. The experimental cross section, adopting the results of powdered and solid samples for energy ranges above and below the Bragg cut-off respectively, agreed well with the calculation which was performed for the samples in perfect polycrystalline state.