scholarly journals Calibrating SANS data for instrument geometry and pixel sensitivity effects: access to an extendedQrange

2017 ◽  
Vol 50 (5) ◽  
pp. 1382-1394 ◽  
Author(s):  
Lukas Karge ◽  
Ralph Gilles ◽  
Sebastian Busch
Keyword(s):  
Small Angle ◽  
Proportional Counter ◽  
Small Angle Neutron Scattering ◽  
Reduction Procedure ◽  
Reference Measurement ◽  
Separate Step ◽  
Position Sensitive ◽  
Improved Data Reduction ◽  
Sans Data ◽  
Geometric Effects

An improved data-reduction procedure is proposed and demonstrated for small-angle neutron scattering (SANS) measurements. Its main feature is the correction of geometry- and wavelength-dependent intensity variations on the detector in a separate step from the different pixel sensitivities: the geometric and wavelength effects can be corrected analytically, while pixel sensitivities have to be calibrated to a reference measurement. The geometric effects are treated for position-sensitive3He proportional counter tubes, where they are anisotropic owing to the cylindrical geometry of the gas tubes. For the calibration of pixel sensitivities, a procedure is developed that is valid for isotropic and anisotropic signals. The proposed procedure can save a significant amount of beamtime which has hitherto been used for calibration measurements.

A new high-resolution small-angle X-ray scattering apparatus using a fine-focus rotating anode, point-focusing collimation and a position-sensitive proportional counter

1984 ◽  
Vol 17 (5) ◽  
pp. 337-343 ◽  
Author(s):  
O. Yoda
Keyword(s):  
High Resolution ◽  
Small Angle ◽  
Proportional Counter ◽  
Anisotropic Scattering ◽  
Photon Flux ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Position Sensitive ◽  
Ray Scattering

A high-resolution small-angle X-ray scattering camera has been built, which has the following features. (i) The point collimation optics employed allows the scattering cross section of the sample to be directly measured without corrections for desmearing. (ii) A small-angle resolution better than 0.5 mrad is achieved with a camera length of 1.6 m. (iii) A high photon flux of 0.9 photons μs−1 is obtained on the sample with the rotating-anode X-ray generator operated at 40 kV–30 mA. (iv) Incident X-rays are monochromated by a bent quartz crystal, which makes the determination of the incident X-ray intensity simple and unambiguous. (v) By rotation of the position-sensitive proportional counter around the direct beam, anisotropic scattering patterns can be observed without adjusting the sample. Details of the design and performance are presented with some applications.

scholarly journals High-pressure small-angle neutron scattering studies of glucose isomerase conformation in solution

2009 ◽  
Vol 42 (3) ◽  
pp. 461-468 ◽  
Author(s):  
Ewa Banachowicz ◽  
Maciej Kozak ◽  
Adam Patkowski ◽  
Gerhard Meier ◽  
Joachim Kohlbrecher
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Electrostatic Interactions ◽  
Xylose Isomerase ◽  
Glucose Isomerase ◽  
Secondary Standard ◽  
High Structural Stability ◽  
Streptomyces Rubiginosus ◽  
Sans Data

Small-angle neutron scattering (SANS) of solutions of glucose/xylose isomerase fromStreptomyces rubiginosuswas measured as a function of pressure. It is shown that the structure of the enzyme in solution as seen by SANS is practically the same as that in the crystal and does not change with pressure up to 150 MPa. This reflects the unusually high structural stability of this material, which makes it extremely interesting to use as a secondary standard for pressure-dependent SANS experiments. This lack of pressure dependence of the SANS data also indicates that any possible change in hydration of the protein induced by pressure is not visible in the SANS curves. An appropriate correction procedure must be used for the SANS data in order to account for the distortion of the intensity curve due to hard-sphere and electrostatic interactions. After this correction, the isomerase can be readily used as a secondary standard for SANS measurements.

An imaging-plate detector for small-angle neutron scattering

2000 ◽  
Vol 33 (5) ◽  
pp. 1253-1261 ◽  
Author(s):  
Y. T. Cheng ◽  
D. F. R. Mildner ◽  
H. H. Chen-Mayer ◽  
V. A. Sharov ◽  
C. J. Glinka
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Imaging Techniques ◽  
Neutron Imaging ◽  
Small Samples ◽  
Imaging Plate ◽  
Position Sensitive ◽  
Transfer Method ◽  
Imaging Plates

Small-angle neutron scattering (SANS) measurements have been performed on long-flight-path pinhole-collimation SANS instruments using, as a two-dimensional position-sensitive detector, both a neutron imaging plate, incorporating gadolinium, and a two-step transfer method, with dysprosium foil as the image transfer medium. The measurements are compared with corresponding data taken using conventional position-sensitive gas proportional counters on the SANS instruments in order to assess the viability of the imaging techniques. The imaging plates have pixel sizes of about two orders of magnitude smaller than those of the gas proportional counter. The reduced pixel size provides definite advantages over the gas counter in certain specific situations, namely when limited space necessitates a short sample-to-detector distance, when only small samples (comparable in size to the detector pixels) are available, or when used in conjunction with focusing beam optics.

A Study of Tio2 Aerogels Pore and Ramified Structure by Small-Angle Neutron Scattering

1994 ◽  
Vol 376 ◽  
Author(s):  
Zhu Zhu ◽  
Min Lin ◽  
Geula Dagan ◽  
Micha Tomkiewicz
Keyword(s):  
Titanium Dioxide ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Gas Adsorption ◽  
Scattering Data ◽  
Morphological Parameters ◽  
Nitrogen Gas ◽  
Light Density ◽  
Sans Data

ABSTRACTThe microstructral characteristics of titanium dioxide aerogels were studied by Small Angle Neutron Scattering (SANS). A variety of models were used to extract the morphological parameters from the SANS data. The evaluation of scattering data was found to be consistent with nitrogen gas adsorption and TEM measurements of a model of aerogel consisting of a light density matrix in which meso- and macro-pores are embedded.

Phase Separation In Blends of Polystyrene and Poly (P-METHYLSTYRENE) Using Thermal Analysis And Small-Angle Neutron Scattering

1993 ◽  
Vol 321 ◽  
Author(s):  
A. Xenopoulos ◽  
J. D. Londono ◽  
G. D. Wígnall ◽  
B. Wunderlich
Keyword(s):  
Thermal Analysis ◽  
Phase Separation ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Small Difference ◽  
Glass Transitions ◽  
Scanning Calorimetry ◽  
Reliable Detection ◽  
Sans Data

ABSTRACTDifferential scanning calorimetry (DSC) was used to study blends of polystyrene (PS) and poly (p-Methylstyrene) (PpmS). The presence of two glass transitions on heating after quenching was interpreted as evidence of phase separation at the temperature of the liquid before quenching. The small difference between the glass transitions of the homopolymers in the PS/PpmS system of “13 K limits the reliable detection of double glass transitions for blends to concentrations between 30 and 70%. The results of the DSC technique are supported by comparison with small angle neutron scattering (SANS) data.

The small-angle neutron scattering spectrometer at the University of Missouri research reactor

1981 ◽  
Vol 14 (6) ◽  
pp. 370-382 ◽  
Author(s):  
D. F. R. Mildner ◽  
R. Berliner ◽  
O. A. Pringle ◽  
J. S. King
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Research Reactor ◽  
Pyrolytic Graphite ◽  
Flight Path ◽  
University Of Missouri ◽  
Beam Incident ◽  
Position Sensitive ◽  
The University

A small-angle neutron scattering (SANS) spectrometer has been constructed at the University of Missouri Research Reactor Facility (MURR). The design of the MURR–SANS is unusual in that the size of the reactor containment building constrains the flight path to be vertical. This is achieved by Bragg scattering upward through 90° from a set of slightly misaligned pyrolytic graphite crystals to provide a neutron beam at 4.75 Å with a wavelength spread of approximately 4.1%. The beam incident on the sample is defined by two matched variable apertures located either 3.0 or 4.5 m apart. The evacuated scattered flight path is designed with removable extensions to match the primary flight path in length. The instrument has an automatic sample handling capability provided by its own dedicated PDP 11/03 computer. The detector is a large assembly of commercially available linear 3He detectors as an economic alternative to a crossed-wire two-dimensional multi-detector. An array of 43 position-sensitive proportional counters, 24 in (609.6 mm) long and 0.5 in (12.7 mm) in diameter, using charge division gives a spatial resolution of 5 x 12.7 mm. The area-averaged detector efficiency is about 84% at a wavelength of 4.75 Å. The range of scattering vectors that can be measured is 0.005 < Q< 0.15 Å−1. The instrument is well suited to a wide variety of experiments on specimens having characteristic dimensions between 20 and 500 Å. MURR–SANS is designed as a user-oriented facility which provides both reasonable resolution and intensity on sample at a modest cost, and forms part of a neutron scattering center.

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