[en] The reflectivity of supermirror has been enhanced by using ion polishing technique in combination with ion beam sputtering system. The dependencies of ion polishing time, ion acceleration energy and incidence angle on the interface roughness were studied to optimize the conditions of Ar+ ion polishing by using and neutron reflectometry. Based on the optimal ion polishing condition, aNi/Ti supermirror with 3Qc were fabricated and characterized. The reflectivity has been increased, and it reached 87% at the critical angle of total reflection

[en] A charge coupled device (CCD) camera with a scintillator coated fiber optic plate (FOP) was examined for neutron imaging. The FOP coupling and the lens coupling in terms of efficient optical coupling with a CCD, and ⁶LiF:ZnS(Ag) and Gd₂O₂S(Tb) in terms of light emission efficiency and spatial resolution were discussed. The spatial resolution for each imaging system was obtained as edge spread functions or observations of modulation transfer function charts

[en] The reflectivity of Ni/Ti supermirror with 3Qc has been enhanced by using ion-polishing technique in combination with an ion-beam sputtering system. The dependencies of ion-polishing time, ion acceleration energy and incidence angle on the interface roughness were firstly studied to optimize the conditions of Ar⁺ ion polishing by using X-ray and neutron reflectometry. Based on the optimal ion-polishing condition, Ni/Ti supermirrors with 3Qc were fabricated and characterized. The reflectivity has been increased, and it reached 87% at the critical angle of total reflection

[en] An introduction to neutron detectors that includes neutron detection principle, detector types, and how to choose a detector is described. (author)

[en] A micro-strip gas chamber (MSGC) has been under development as a two-dimensional position sensitive detector for neutron scattering experiments at the high-intensity proton accelerator facilities. The MSGC requirements as a neutron detector are high counting rate, high detection efficiency, high positional resolution, stability and large area coverage. The purpose of this paper is to verify the properties of Gadolinium as a MSGC converter. The arrangements of a capillary plate and MSGC gas pressure have been optimized by simulation of a Gadolinium converter. As a result of that, a position resolution of 160 μm and n/γ ratio of 200 were obtained at the gas pressure of 0.02 atm. In view of γ-ray sensitivity, the further improvement is required for practical applications

[en] Development of the neutron optical devices at JRR-3M is reported. In order to reduce the interface roughness and enhance to the reflectivity of supermirrors, ion polishing technique has been investigated for Ni/Ti multilayers. The optimum ion beam conditions of ion polishing time, ion energy and incident angle were determined, and the reflectivity of Ni/Ti has been successfully enhanced. For the application of supermirror, replacing program that a natural nickel guide tube is replaced with supermirror guide tube is in progress at JRR-3M. It is evaluated that the total intensity at the end of a supermirror guide tube is 5.6 times that of the exiting nickel guide tube using Monte-Carlo code. A neutron bender, which can deflect a white'-spectrum beam from a main beam line and thereby supply a wide range of wavelengths to a new instruments, was developed. (author)

[en] To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering by thin film, roughness of surface of thin film, correlation function, neutron propagation by thin film, diffuse scattering by DWBA theory, measurement model, SDIFFF (neutron diffuse scattering analysis program by thin film) and simulation results are explained. On neutron diffuse scattering by multilayer film, roughness of multilayer film, principle of diffuse scattering, measurement method and simulation examples by MDIFF (neutron diffuse scattering analysis program by multilayer film) are explained. (S.Y.)To research surface structure of thin film and multilayer film by neutron, a neutron diffuse scattering analysis code using DWBA (Distorted-Wave Bron Approximation) principle was developed. Subjects using this code contain the surface and interface properties of solid/solid, solid/liquid, liquid/liquid and gas/liquid, and metal, magnetism and polymer thin film and biomembran. The roughness of surface and interface of substance shows fractal self-similarity and its analytical model is based on DWBA theory by Sinha. The surface and interface properties by diffuse scattering are investigated on the basis of the theoretical model. The calculation values are proved to be agreed with the experimental values. On neutron diffuse scattering by thin film, roughness of surface of thin film, correlation function, neutron propagation by thin film, diffuse scattering by DWBA theory, measurement model, SDIFFF (neutron diffuse scattering analysis program by thin film) and simulation results are explained. On neutron diffuse scattering by multilayer film, roughness of multilayer film, principle of diffuse scattering, measurement method and simulation examples by MDIFF (neutron diffuse scattering analysis program by multilayer film) are explained. (S.Y.)

No abstract available

No abstract available

[en] The energy deposition in NSRR U₃Si₂-Al fuel plates has been evaluated in this report. It was assumed that one test plate was irradiated transiently in NSRR experiment hole. The uranium density in the fuel meet ranged between 2.15 gU/cm³ and 5.01 gU/cm³. The length of fuel plate ranged between 10.0 cm and 20.0 cm. The average energy deposition in the fuel plate which uranium density is 5.01 gU/cm³ and fuel length is 15.0 cm, is 548.6 cal/g/100 MW/sec. The melting point of U₃Si₂ is 1938 K. The test plate is melt at the energy deposition which is 225.4 cal/g (density 12.2 g), so the test plate will be melt by NSRR experiment. According to increase in uranium density, the average energy deposition in unit volume increase, but that in unit mass dicrease. The energy deposition distribution is rose up at the top and bottom of the test plate, and it is flat at the center of it. (author)