Journal ArticleDOI
Design and performance of a thermal-neutron double-crystal diffractometer for USANS at NIST
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TLDR
An ultra-high-resolution small-angle neutron scattering (USANS) double-crystal diffractometer (DCD) is now in operation at the NIST Center for Neutron Research (NCNR), which uses multiple reflections from large silicon (220) perfect single crystals, before and after the sample, to produce both high beam intensity and a low instrument background suitable for smallangle scattering measurements.Abstract:
An ultra-high-resolution small-angle neutron scattering (USANS) double-crystal diffractometer (DCD) is now in operation at the NIST Center for Neutron Research (NCNR). The instrument uses multiple reflections from large silicon (220) perfect single crystals, before and after the sample, to produce both high beam intensity and a low instrument background suitable for small-angle scattering measurements. The minimum detector background to beam intensity ratio (noise-to-signal, N/S) for q ≥ 5 × 10−4 A−1 is 4 × 10−7. The instrument uses 2.38 A wavelength neutrons on a dedicated thermal neutron beam port, producing a peak flux on the sample of 17300 cm−2 s−1. The typical measurement range of the instrument extends from 3 × 10−5 A−1 to 5 × 10−3 A−1 in scattering wavevector (q), providing information on material structure over the size range from 0.1 µm to 20 µm. This paper describes the design and characteristics of the instrument, the mode of operation, and presents data that demonstrate the instrument's performance.read more
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Reduction and analysis of SANS and USANS data using IGOR Pro
TL;DR: A graphical interface has been developed to visualize and quickly reduce raw SANS and USANS data into one- or two-dimensional formats for interpretation, allowing users to contribute code and models for distribution to all users.
Journal ArticleDOI
Pore structure characterization of North American shale gas reservoirs using USANS/SANS, gas adsorption, and mercury intrusion
Christopher R. Clarkson,Nisael A. Solano,Robert Marc Bustin,Amanda M. M. Bustin,Gareth R.L. Chalmers,Lilin He,Yuri B. Melnichenko,A.P. Radlinski,A.P. Radlinski,Tomasz Blach +9 more
TL;DR: In this paper, small-angle and ultra-small-angle neutron scattering (SANS and USANS), low-pressure adsorption (N2 and CO2), and high-pressure mercury intrusion measurements were performed on a suite of North American shale reservoir samples providing the first ever comparison of all these techniques for characterizing the complex pore structure of shales.
Journal ArticleDOI
Composition and density of nanoscale calcium–silicate–hydrate in cement
TL;DR: This study measures the composition and solid density of the principal binding reaction product of cement hydration, calcium-silicate-hydrate (C-S-H) gel, one of the most complex of all gels, and quantifies a nanoscale calcium hydroxide phase that coexists with C- S-H gel.
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Characterization and Analysis of Porosity and Pore Structures
TL;DR: There are a large number of methods for quantifying porosity, and an increasingly complex idea of what it means to do so as discussed by the authors, which is why it is important to quantify the relationships between porosity and storage, transport and rock properties, however, the pore structure must be measured and quantitatively described.
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Porosity of Coal and Shale: Insights from Gas Adsorption and SANS/USANS Techniques
TL;DR: In this paper, the porosity and pore accessibility of coal and shale samples were studied with respect to their porosity, and the results demonstrate that there is a major difference in mesopore (2-50 nm) size distribution between the coal and the shale samples, while there was a close similarity in micropore (<2 nm).
References
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Book
Theory of X-Ray Diffraction in Crystals
TL;DR: A classie work, so thoroughly revised as to be essentially a new book as mentioned in this paper, has been published, which includes: a new mineral classification; a new elastic series of classification numbers for species; new data derived from x-ray crystallography, and a new form of presentation of crystallographic data; revision of specific gravities, based on new observations; introduction of the optical characters of the opaque minerals; new chemical treatment of species.
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The 30 m Small-Angle Neutron Scattering Instruments at the National Institute of Standards and Technology
TL;DR: In this paper, two high-resolution, general-purpose, small-angle neutron scattering instruments have been constructed at the National Institute of Standards and Technology's Center for Neutron Research.
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Oxygen precipitation in silicon
TL;DR: A review of the recent advances in the study of oxygen precipitation and of the main properties of oxide precipitates in silicon is presented in this article, where the most important techniques for the characterization of the precipitates are illustrated together with the most interesting and recent results.
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Neutron Cross-Sections
TL;DR: Neutron Cross Sections Prepared by the United States Atomic Energy Commission (Selected Reference Material on Atomic Energy) Pp viii + 328 (London: McGraw-Hill Publishing Company, Ltd, 1955) 90s as discussed by the authors