Study of a multi-pinhole collimation system based small-angle neutron scattering instrument at the Compact Pulsed Hadron Source

2018 ◽  
Vol 51 (6) ◽  
pp. 1605-1615
Author(s):  
Zhiyuan Wang ◽  
Huarui Wu ◽  
Liang Chen ◽  
Liangwei Sun ◽  
Xuewu Wang
Keyword(s):  
Neutron Scattering ◽  
Sample Size ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Signal To Noise Ratio ◽  
Safety Margin ◽  
Beam Intensity ◽  
Opening Angle ◽  
Collimation System ◽  
Sans Instrument

The neutron flux of the Compact Pulsed Hadron Source (CPHS) is about 2–3 orders of magnitude lower than that of large neutron sources, which means that the beam intensity should be improved to achieve good statistics. Multi-pinhole collimation can be used to obtain a lower Q with an acceptable beam intensity in a very small angle neutron scattering (VSANS) instrument and a higher beam intensity for a larger sample size in a small-angle neutron scattering (SANS) instrument. A new nine-pinhole structure is used in a SANS instrument at CPHS to achieve an acceptable range and resolution of Q and a higher beam intensity compared to single-pinhole collimation. The crosstalk issue associated with multi-pinhole collimation is addressed using an optimized algorithm to achieve a higher safety margin and a larger pinhole size with a higher beam intensity at the sample. Different collimator aperture structures are compared on the basis of their noise production. Experiments are performed to verify the theory of calculating reflection noise from the inner surface of the collimator's aperture and parasitic noise from the beveled collimator structure. From a simulated SANS experiment using cold neutrons in the SANS instrument, it is clarified that multi-pinhole collimators with an opening angle on the downstream side have better performance than those with an opening angle on the upstream side and straight-cut collimators. Compared with a single-pinhole collimation system, a nine-pinhole collimation system increases the intensity at the sample by approximately sevenfold when the sample size is increased by 20-fold for CPHS-SANS, and the signal-to-noise ratio is improved by exploiting a specific collimator aperture structure. Our goal is to install a multi-pinhole collimator based SANS instrument at CPHS in the future, and it is hoped that these results will serve to promote the utilization of multi-pinhole collimation systems at other facilities.

Resolution of small-angle neutron scattering with a refractive focusing optic

2005 ◽  
Vol 38 (3) ◽  
pp. 488-492 ◽  
Author(s):  
D. F. R. Mildner
Keyword(s):  
Neutron Scattering ◽  
Sample Size ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Instrumental Performance ◽  
Collimation System ◽  
Analytic Expression ◽  
Focusing Lens

A small-angle neutron scattering spectrometer that uses a refractive focusing optic can reach smaller values of the scattering vector, and with higher resolution, than that using pinhole collimation. The analytic expression for the resolution is independent of the sample size for one wavelength only, when the focusing lens images the source at the detector. At all other wavelengths the contribution from the sample size is non-zero. For a system that uses a range of wavelengths to increase the intensity without significantly degrading the instrumental performance, the contribution from the sample term is not zero, though it is small and less than that for the pinhole collimation system.

scholarly journals Effect of Particle Size on Pore Characteristics of Organic-Rich Shales: Investigations from Small-Angle Neutron Scattering (SANS) and Fluid Intrusion Techniques

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6049
Author(s):  
Yi Shu ◽  
Yanran Xu ◽  
Shu Jiang ◽  
Linhao Zhang ◽  
Xiang Zhao ◽  
...  
Keyword(s):  
Particle Size ◽  
Neutron Scattering ◽  
Sample Size ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Particle Surface ◽  
Size Fraction ◽  
Future Research ◽  
Pore Characteristics ◽  
Optimum Sample Size

The sample size or particle size of shale plays a significant role in the characterization of pores by various techniques. To systematically investigate the influence of particle size on pore characteristics and the optimum sample size for different methods, we conducted complementary tests on two overmature marine shale samples with different sample sizes. The tests included small-angle neutron scattering (SANS), gas (N2, CO2, and H2O) adsorption, mercury injection capillary pressure (MICP), and field emission-scanning electron microscopy (FE-SEM) imaging. The results indicate that artificial pores and fractures may occur on the surface or interior of the particles during the pulverization process, and some isolated pores may be exposed to the particle surface or connected by new fractures, thus improving the pore connectivity of the shale. By comparing the results of different approaches, we established a hypothetical model to analyze how the crushing process affects the pore structure of overmature shales. Our results imply that intact wafers with a thickness of 0.15–0.5 mm and cubic samples (~1 cm3) are optimal for performing SANS and MICP analyses. Meanwhile, the 35–80 mesh particle size fraction provides reliable data for various gas physisorption tests in overmature shale. Due to the intrinsic heterogeneity of shale, future research on pore characteristics in shales needs a multidisciplinary approach to obtain a more comprehensive, larger scale, and more reliable understanding.

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.

scholarly journals A Unified User-Friendly Instrument Control and Data Acquisition System for the ORNL SANS Instrument Suite

2021 ◽  
Vol 11 (3) ◽  
pp. 1216
Author(s):  
Xingxing Yao ◽  
Blake Avery ◽  
Miljko Bobrek ◽  
Lisa Debeer-Schmitt ◽  
Xiaosong Geng ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Data Acquisition System ◽  
Acquisition System ◽  
Instrument Control ◽  
User Friendly ◽  
Sans Instrument ◽  
New System

In an effort to upgrade and provide a unified and improved instrument control and data acquisition system for the Oak Ridge National Laboratory (ORNL) small-angle neutron scattering (SANS) instrument suite—biological small-angle neutron scattering instrument (Bio-SANS), the extended q-range small-angle neutron scattering diffractometer (EQ-SANS), the general-purpose small-angle neutron scattering diffractometer (GP-SANS)—beamline scientists and developers teamed up and worked closely together to design and develop a new system. We began with an in-depth analysis of user needs and requirements, covering all perspectives of control and data acquisition based on previous usage data and user feedback. Our design and implementation were guided by the principles from the latest user experience and design research and based on effective practices from our previous projects. In this article, we share details of our design process as well as prominent features of the new instrument control and data acquisition system. The new system provides a sophisticated Q-Range Planner to help scientists and users plan and execute instrument configurations easily and efficiently. The system also provides different user operation interfaces, such as wizard-type tool Panel Scan, a Scripting Tool based on Python Language, and Table Scan, all of which are tailored to different user needs. The new system further captures all the metadata to enable post-experiment data reduction and possibly automatic reduction and provides users with enhanced live displays and additional feedback at the run time. We hope our results will serve as a good example for developing a user-friendly instrument control and data acquisition system at large user facilities.

On the design and experimental realization of a multislit-based very small angle neutron scattering instrument at the European Spallation Source

2015 ◽  
Vol 48 (4) ◽  
pp. 1242-1253 ◽  
Author(s):  
Sohrab Abbas ◽  
Sylvain Désert ◽  
Annie Brûlet ◽  
Vincent Thevenot ◽  
Patrice Permingeat ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Feasibility Studies ◽  
Experimental Realization ◽  
Order Of Magnitude ◽  
Spallation Source ◽  
Length Scaling ◽  
First Time ◽  
Sans Instrument

This article reports the design of a versatile multislit-based very small angle neutron scattering (VSANS) instrument working either as a dedicated instrument or as an add-on for any small-angle neutron scattering machine like the proposed SANS instrument, SKADI, at the future European Spallation Source. The use of multiple slits as a VSANS collimator for the time-of-flight techniques has been validated usingMcStassimulations. Various instrument configurations to achieve different minimum wavevector transfers in scattering experiments are proposed. The flexibility of the multislit VSANS instrument concept is demonstrated by showing the possibility of instrument length scaling for the first time, allowing access to varying minimum wavevector transfers with the same multislit setup. These options can provide smooth access to minimum wavevector transfers lower than ∼4 × 10−5 Å−1and an overlapping of wavevector coverage with normal SANS mode,e.g.with the SKADI wavevector range of 10−3–1.1 Å−1. Such an angularly well defined and intense neutron beam will allow faster SANS studies of objects larger than 1 µm. Calculations have also been carried out for a radial collimator as an alternative to the multislit collimator setup. This extends the SANSQrange by an order of magnitude to 1 × 10−4 Å−1with much simpler alignment. The multislit idea has been realized experimentally by building a prototype at Laboratoire Leon Brillouin, Saclay, with cross-talk-free geometry. Feasibility studies were carried out by making VSANS measurements with single- and multislit collimators, and the results are compared with multiple-pinhole geometry using classical SANS analysis tools.

Novel multiple-beam very small angle neutron scattering (VSANS) using a conventional SANS instrument

2014 ◽  
Vol 47 (4) ◽  
pp. 1180-1189 ◽  
Author(s):  
C. D. Dewhurst
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Neutron Detector ◽  
Small Angle Neutron Scattering ◽  
Single Scattering ◽  
Small Samples ◽  
Neutron Guide ◽  
Multiple Beam ◽  
Order Of Magnitude ◽  
Sans Instrument

This article demonstrates how a small-angle neutron scattering (SANS) instrument, such as D33 at the Institut Laue–Langevin, can be configured without extensive modification to produce multiple highly collimated beams for measurements at the smallest scattering angles. This extends the range of material length scales able to be studied to greater than 1 µm, almost one order of magnitude greater than that of a conventional SANS instrument. The multiple-beam configuration uses the intrinsic properties of the neutron guide system and source and sample apertures with no additional optical devices or precise aperture array alignments. Up to several hundred individual beams, separated in angle by fractions of a degree in both the horizontal and vertical directions, can be extracted, which focus at the sample and diverge towards the distant neutron detector. This is particularly useful for the study of small samples, which can be probed at the smallest scattering angles while retaining sufficient neutron flux because of the use of multiple beams. The resulting data on the area neutron detector consist of multiple scattering or diffraction images which extend over and overlap those produced by neighboring beams. While the principle of the technique is rather simple, analysis of the overlapping SANS patterns requires the development of software techniques to extract the single scattering function.

scholarly journals The extendedQ-range small-angle neutron scattering diffractometer at the SNS

2010 ◽  
Vol 43 (5) ◽  
pp. 1068-1077 ◽  
Author(s):  
J. K. Zhao ◽  
C. Y. Gao ◽  
D. Liu
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Neutron Transport ◽  
Signal To Noise Ratio ◽  
Counting Efficiency ◽  
Target Station ◽  
Oak Ridge ◽  
Wavelength Resolution ◽  
Neutron Momentum

The extendedQ-range small-angle neutron scattering diffractometer (EQ-SANS) at the Spallation Neutron Source (SNS), Oak Ridge, is designed for wide neutron momentum transfer (Q) coverage, high neutron beam intensity and good wavelength resolution. In addition, the design and construction of the instrument aim to achieve a maximum signal-to-noise ratio by minimizing the background. The instrument is located on the high-power target station at the SNS. One of the key components in the primary flight path is the neutron optics, consisting of a curved multichannel beam bender and sections of straight neutron guides. They are optimized to minimize neutron transport loss, thereby maximizing the available flux on the sample. They also enable the avoidance of a direct line of sight to the neutron moderator at downstream locations. The instrument has three bandwidth-limiting choppers. They allow a novel frame-skipping operation, which enables the EQ-SANS diffractometer to achieve a dynamicQrange equivalent to that of a similar machine on a 20 Hz source. The two-dimensional low-angle detector, based on3He tube technologies, offers very high counting rates and counting efficiency. Initial operations have shown that the instrument has achieved its design goals.

scholarly journals Magnetic system for small angle neutron scattering investigations of nanomaterials at YuMO-SANS instrument

2012 ◽  
Vol 351 ◽  
pp. 012022 ◽  
Author(s):  
A I Kuklin ◽  
M Balasoiu ◽  
S A Kutuzov ◽  
Yu S Kovalev ◽  
A V Rogachev ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Magnetic System ◽  
Sans Instrument

Performance of a New Small-Angle Neutron Scattering Instrument at the Malaysian TRIGA Reactor

1997 ◽  
Vol 30 (5) ◽  
pp. 884-888 ◽  
Author(s):  
M. A. M. Sufi ◽  
S. Radiman ◽  
A. Wiedenmann ◽  
K. Mortensen
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Epithermal Neutrons ◽  
Sample Position ◽  
Set Up ◽  
High Level ◽  
Strong Scattering ◽  
Sans Instrument ◽  
Wavelength Distribution

The set-up and alignment of a new small-angle neutron scattering (SANS) instrument, installed at the 1 MW light-water-moderated MINT TRIGA research reactor, are described. The wavelength distribution and the flux at the sample position have been determined. First neutron scattering measurements were made on two reference samples with strong scattering power; the results prove that the SANS signal is well reproduced on the instrument when samples of typical size are used, despite the high level of the background of fast and epithermal neutrons.

Resolution of small-angle neutron scattering with a reflective focusing optic

2014 ◽  
Vol 47 (4) ◽  
pp. 1247-1251 ◽  
Author(s):  
David F. R. Mildner
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Beam Divergence ◽  
Sample Area ◽  
Analytic Expression ◽  
Sans Instrument

A small-angle neutron scattering instrument that uses a reflective focusing optic can achieve smaller values of the scattering vector, and with higher resolution, than the usual pinhole collimation. When the focusing mirror images the source onto the detector, the analytic expression for the resolution is independent of the sample area and is principally determined by the beam divergence incident on the sample, modified by the distance between the optic and the sample. The results are applied to a focusing SANS instrument with axisymmetric mirrors.

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