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[en] The 15 MW Heavy Water Research Reactor (HWRR) at CIAE in Beijing is the only neutron source available for neutron scattering experiments in China currently. A new research reactor, China Advanced Research Reactor (CARR), now is being built at CIAE to meet the increasing demand of neutron scattering research in China. A brief introduction to background of HWRR, CARR and the facilities to be installed at CARR has been given in this paper. (authors)

[en] The crystallographic and magnetic structures of Ho₂Fe₉Ga₈ and Ho₂Fe₉Ga₆Al₂ were studied by powder neutron diffraction at room temperature. The atom fractional occupancies of Ga and Al and the magnetic moments of Ho and Fe were obtained by using Rietveld analysis program. The magnetic structures of the two samples show an easy-axis anisotropy, with the Fe magnetic moment being ferromagnetically coupled to those of Ho

[en] The unfolding spectrum capacity of SAND-II and RDMM methods was investigated using threshold detectors to determine the thermal neutron induced ²³⁵U fission spectrum. A Monte Carlo error analysis code was used to analyse the input data errors. The errors of solution uniqueness for SAND-II and the effect of the weighting function for RDMM have been discussed. The sensitivity of both methods for the structure of the unknown spectra has been tested briefly. The results showed that SAND-II and RDMM are better methods for determinating the fast neutron spectra with smooth variation. The SAND-II is more suitable for unknown spectra with simple structure

[en] A summary on the progress of material texture measurement with neutron diffraction in domestic and abroad was described. A brief outlook on the development of material texture measured with neutron diffraction in he future was also given. (authors)

[en] A method of cutting, editing and printing screen picture in thermal neutron diffraction pattern, which is provided by two profile refinement programs (RIETAN and FULLPROF), is given through the combined application of several software programs on personal computer. This method is useful extensively in the field where cutting and editing screen picture are needed

[en] Running environment and operating method of profile refinement program (RIETAN) in thermal neutron powder diffraction are introduced. The details of inputting parameters and data files and executing RIETAN program are described with metastable Nd₂Fe₂₃B₃ compound as an example

[en] The analysis method of thermal neutron diffraction spectra and how to make the input files (parameters and data) and to execute the RIETAN profile refinement program are introduced in detail. As an example, the refinement process of a rare-earth permanent magnetic compound Ho₂Fe₉Ga₈ was illustrated

[en] Under the action of a DC field, the neutron diffraction intensity of α-LiIO₃ single crystal is enhanced and the width of the rocking curve is widened. Accoording to the appreciable dependence of the widths of the rocking curve on the incident neutron wavelength, it is shown that α-LiIO₃ single crystal becomes the crystal with a gradient in the lattice spacing with the application of a DC field along the crystallographic C-axis

[en] The crystallographic and magnetic structure of Ho₂Fe₉Ga_8-x Al_x (x 2,4) and PrFe_10.5Mo_1.5N_x compounds are studied by powder neutron diffraction. The atom fractional occupancies of Ga, Al, Mo and N and the atom magnetic moments of Ho, Fe and Pr are obtained by Rietveld analysis program. Fro Ho₂Fe₉Ga_8-xAl_x (x = 2,4), the magnetic moments of the phase with the x = 2,4 at 50 K and x = 2 at 300 K show uniaxial magnetic anisotropy. PrFe_10.5Mo_1.5N_x compound exhibits easy-axis magnetic anisotropy, but the anisotropy of PrFe_10.5Mo_1.5 is easy-planar. The crystal structure of D(H)LAP is determined by single crystal neutron diffraction. The results indicate that the deuterium occupy hydrogen positions except those hydrogen atoms bonded to carbon atoms