NEUTRON DEBYE-SCHERRER DIFFRACTION WORKS USING A LINEAR ELECTRON ACCELERATOR

Neutron diffraction patterns were obtained by the time-of-flight method using Tohoku linac for the case of powdered samples as well as for single crystals. Thermal neutron beams of 35-50 μsec pulse width were obtained by poisoned water moderator. Powder patterns of Al at different temperatures have shown many lines of high indices, which enabled to calculate the Debye temperature with considerable accuracy. Several other powdered samples including Si, ZnO were also examined. Magnetic peaks of α-Fe2O3, CaFe2O4 were identified. Count collecting time of 2 or 3 h was enough to reach the reliability R to the level of a several percent. High index lines appeared very conspicuously, in contrast to the reactor-chopper results. The fwhm of the diffraction lines was 2.0-1.5% in case the scattering angle 2θ was 90°. It depended on the energy of diffracting neutrons, becoming smaller for neutrons of wavelength shorter than 1 Å, that is for higher index lines. © 1969.