The 40 m general purpose small-angle neutron scattering instrument at Oak Ridge National Laboratory

作者：George D. Wignall, Kenneth C. Littrell, William T. Heller, Yuri B. Melnichenko, Kathy Bailey, Gary W. Lynn, Dean A. A. Myles, Volker S. Urban, Michelle V. Buchanan, Douglas L. Selby, Paul D. Butler · 发表于：Journal of Applied Crystallography · 年份：2012 · DOI：10.1107/s0021889812027057 · 被引用次数：105 · 研究领域：Nuclear Physics and Applications、Atomic and Subatomic Physics Research、Radiation Detection and Scintillator Technologies

A series of upgrades have been undertaken at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, including the installation of a supercritical hydrogen moderator (T≃ 20 K), which has boosted the flux of long-wavelength neutrons by over two orders of magnitude. In order to take advantage of the new capabilities, a 40 m-long small-angle neutron scattering (SANS) instrument has been constructed, which utilizes a mechanical velocity selector, pinhole collimation and a high-count-rate (>105 Hz) large-area (1 m2) two-dimensional position-sensitive detector. The incident wavelength (λ), resolution (Δλ/λ), incident collimation and sample-to-detector distance are independently variable under computer control. The detector can be moved up to 45 cm off-axis to increase the overallQrange [<0.001 <Q= (4π/λ)sinθ < 1 Å−1, where 2θ is the angle of scatter]. The design and characteristics of this instrument are described, along with examples of scattering data to illustrate the performance.