18 January 1989 Nickel Mirror And Supermirror Neutron Guide Tubes At The Kyoto University Research Reactor
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We installed the first nickel mirror neutron guide tube with a characteristic wavelength of 2.85 Å at Kyoto University research reactor(KUR, 5MW, cooled and moderated by light water) in 1973 and a supermirror guide tube with a characteristic wavelength of 1.17 Å in 1984, in order to get more intense thermal neutron beam. Four guide tubes are under construction at a cold neutron source installed in 1986. Two of them are supermirror type with a characteristic wavelength of 3 Å and the others are supermirror and Ni-mirror type with characteristic wavelengths of 6 Å and 23 Å, respectively. Supermirrors are made by automatically controlled vacuum deposition of nickel and titanium metal with electron gun. Their averaging reflectivity for the first supermirror guide tube are the following: The apparent critical wavelength, λ/θ, of reflection is 240 Å in term of wavelength(λ/θ) corresponding to the component of wave number perpendicular to the mirror surface. The reflectivity is 0.65 at the apparent critical wavelength and becomes higher with increasing neutron wavelength up to nearly unity for wavelength longer than 500 Å. Supermirror guide tubes are featured by more available neutrons with larger divergent angles and shorter length of the guide tubes. These features would bring us significant advantages depending on experimental requirements.
© (1989) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Toru Ebisawa, Tsunekazu Akiyoshi, Seiji Tasaki, Takeshi Kawai, Norio Achiwa, Masahiko Utsuro, Sunao Okamoto, "Nickel Mirror And Supermirror Neutron Guide Tubes At The Kyoto University Research Reactor", Proc. SPIE 0983, Thin Film Neutron Optical Devices: Mirrors, Supermirrors, Multilayer Monochromators, Polarizers, and Beam Guides, (18 January 1989); doi: 10.1117/12.948746; https://doi.org/10.1117/12.948746

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