scholarly journals Grazing-incidence small-angle neutron scattering from structures below an interface

2017 ◽  
Vol 50 (4) ◽  
pp. 1066-1074 ◽  
Author(s):  
Shirin Nouhi ◽  
Maja S. Hellsing ◽  
Vassilios Kapaklis ◽  
Adrian R. Rennie
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Grazing Angle ◽  
Grazing Incidence ◽  
Angle Of Incidence ◽  
Model Calculations ◽  
Self Organized ◽  
Incoming Beam ◽  
Sample Structure

Changes of scattering are observed as the grazing angle of incidence of an incoming beam increases and probes different depths in samples. A model has been developed to describe the observed intensity in grazing-incidence small-angle neutron scattering (GISANS) experiments. This includes the significant effects of instrument resolution, the sample transmission, which depends on both absorption and scattering, and the sample structure. The calculations are tested with self-organized structures of two colloidal samples with different size particles that were measured on two different instruments. The model allows calculations for various instruments with defined resolution and can be used to design future improved experiments. The possibilities and limits of GISANS for different studies are discussed using the model calculations.

Conceptual design of the grazing-incidence focusing small-angle neutron scattering (gif-SANS) instrument at CPHS

2021 ◽  
pp. 1-5
Author(s):  
Huarui Wu ◽  
Weihang Hong ◽  
Yao Zhang ◽  
Pulin Bai ◽  
Wenbo Mo ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Conceptual Design ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
High Performance ◽  
Grazing Incidence ◽  
The Other ◽  
Tsinghua University ◽  
Neutron Sources ◽  
Sans Instrument

Developing small-angle neutron scattering techniques at compact accelerator-driven neutron sources (CANS) is of great importance for expanding the user community and advancing CANS capability. At the Compact Pulsed Hadron Source (CPHS) at Tsinghua University, neutron-focusing mirrors are under intensive research to address the challenge. A grazing-incidence focusing SANS (gif-SANS) project is initialized. It employs a nested supermirror assembly with a large collecting area to achieve ⩾ 10 5 n/s neutron intensity at Q min ⩽ 0.007 Å − 1 . It will equip two detectors, one being a 3He detector for normal Q-range measurements, and the other being a high-resolution detector for extending the Q min down to 10 − 3 Å − 1 . In this work, we present the conceptual design of the gif-SANS at CPHS. Such a scheme is conducive to enable high-performance SANS measurements at CANS.

Small-angle neutron scattering method for in situ studies of the dense cores of biological cells and vesicles: application to isolated neurosecretory vesicles

1989 ◽  
Vol 22 (6) ◽  
pp. 546-555 ◽  
Author(s):  
S. Krueger ◽  
J. W. Lynn ◽  
J. T. Russell ◽  
R. Nossal
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Method ◽  
Contrast Variation ◽  
Model Calculations ◽  
The Core ◽  
Dense Cores ◽  
Dense State

Small-angle neutron scattering was used to study the structure of the dense cores of intact neurosecretory vesicles (NSV). Contrast-variation techniques were used to minimize the scattering due to vesicle membranes and emphasize that due to the cores. By examination of a suspension of NSV membranes along with the intact NSV, residual membrane scattering was suppressed. The resultant scattering is inconsistent with model calculations which assume that the dense state of the vesicle cores is achieved by random dense packing or crystallization of small globular particles. Rather, the data suggest that the core constituents exist in a disordered state, forming aggregates with radii of gyration significantly larger than 100 Å.

scholarly journals Microstructure and water distribution in catalysts for polymer electrolyte fuel cells, elucidated by contrast variation small-angle neutron scattering

2019 ◽  
Vol 52 (4) ◽  
pp. 791-799 ◽  
Author(s):  
Satoshi Koizumi ◽  
Satoru Ueda ◽  
Takumi Inada ◽  
Yohei Noda ◽  
Robert A. Robinson
Keyword(s):  
Fuel Cells ◽  
Neutron Scattering ◽  
Polymer Electrolyte ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Water Distribution ◽  
Grazing Incidence ◽  
Polymer Electrolyte Fuel Cells ◽  
Contrast Variation ◽  
Mixed Water

By using small-angle neutron scattering (SANS) reinforced by scanning electron microscopy, the fine structure of catalysts for polymer electrolyte fuel cells has been investigated. The experimental data resulting from contrast variation with mixed light and heavy water (H2O/D2O) are well described by a core–shell model with fluctuations in concentration between water and Nafion. In particular, SANS obtained with the mixed water ratio 30/70, which corresponds to a matching point between mixed water and Nafion, shows a broad scattering maximum, which is attributed to a 5 nm-thick Nafion shell on the surface of the larger carbon particles. After swelling by water, the ionomer layer absorbs water at the 17 wt% level. By changing the H2O/D2O ratio, it was further confirmed that the catalyst with the ionomer exhibits water repellence, whereas the bare catalyst without the ionomer is wetted by water. Because it is very difficult to extract more information, for instance regarding the Pt–Nafion interactions, by means of small-angle scattering, reflectometry and grazing-incidence scattering experiments with neutrons should be attempted on a model catalyst prepared on a flat substrate.

scholarly journals Time-of-flight grazing incidence small angle neutron scattering on Gd nanowires

2009 ◽  
Vol 167 (1) ◽  
pp. 73-79 ◽  
Author(s):  
W. Kreuzpaintner ◽  
J.-F. Moulin ◽  
D. Lott ◽  
R. Kampmann ◽  
M. Haese-Seiller ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Time Of Flight ◽  
Grazing Incidence

Morphology determination of defect-rich diblock copolymer films with time-of-flight grazing-incidence small-angle neutron scattering

2014 ◽  
Vol 47 (4) ◽  
pp. 1228-1237 ◽  
Author(s):  
Peter Müller-Buschbaum ◽  
Gunar Kaune ◽  
Martin Haese-Seiller ◽  
Jean-Francois Moulin
Keyword(s):  
Neutron Scattering ◽  
Diblock Copolymer ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Microphase Separation ◽  
Time Of Flight ◽  
Surface Region ◽  
Grazing Incidence ◽  
Near Surface ◽  
Oriented Parallel

The complex nanomorphology of a defect-rich deuterated poly(styrene-block-methyl methacrylate), P(S-b-MMAd), diblock copolymer film is determined with a combination of grazing-incidence small-angle neutron scattering (GISANS) and time-of-flight (TOF) mode. TOF-GISANS enables the simultaneous performance of several GISANS measurements that differ in wavelength. The resulting set of GISANS data covers different ranges of the scattering vector and has different scattering depths. Thus surface-sensitive and bulk-sensitive measurements can be performed simultaneously. The P(S-b-MMAd) film exhibits a lamellar microphase separation structure, which because of the defects is arranged into small, randomly oriented grains, composed of four–five lamellar repetitions. In the near-surface region, the lamellar structure is oriented parallel to the substrate, which explains the smooth surface found with atomic force microscopy.

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