Study on Calibrating Neutron Velocity Selector of Small Angle Neutron Scattering Instrument

2013 ◽  
Vol 433-435 ◽  
pp. 837-843
Author(s):  
Zhou Xiang Yu ◽  
Yun Tao Liu ◽  
He Cheng ◽  
Li Zhang ◽  
Dong Feng Chen
Keyword(s):  
Measurement Error ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Dead Time ◽  
Resolution Rate ◽  
Upper Limits ◽  
Wavelength Resolution ◽  
Total Measurement Time ◽  
First Time

Neutron velocity selector is widely used on neutron scattering instruments as key component. To calibrate it (wavelength and wavelength-resolution-rate measurement), it is necessary to design calibration instrument and develop calibration technique. Based on small angle neutron scattering instrument (SANS) at China Advanced Research Reactor (CARR), instrument structure was designed and instrument parameters were determined. Count loss influence on measurement of wavelength resolution rate (WRR) was studied for the first time. Measurement error of WRR is decided by product of dead time and Gauss peak count rate (GPCR) and increases with increasing GPCR for the same dead time. In order to ensure WRR measurement error less than 0.9%, upper limits of GPCR for detector adjoining chopper and detector far away from chopper are less than 10000[s-1] and 2500[s-1] respectively. According to upper limits of GPCR, floor limit of total measurement time for each spectrum is calculated to be 6.66 minutes.

scholarly journals Tuning the instrument resolution using chopper and time of flight at the small-angle neutron scattering diffractometer KWS-2

2015 ◽  
Vol 48 (6) ◽  
pp. 1849-1859 ◽  
Author(s):  
Aurel Radulescu ◽  
Noémi Kinga Székely ◽  
Stephan Polachowski ◽  
Marko Leyendecker ◽  
Matthias Amann ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Neutron Scattering ◽  
Small Angle ◽  
High Intensity ◽  
Small Angle Neutron Scattering ◽  
Time Of Flight ◽  
Standard Samples ◽  
Experimental Resolution ◽  
Wavelength Resolution ◽  
At Will

Following demand from the user community regarding the possibility of improving the experimental resolution, the dedicated high-intensity/extendedQ-range SANS diffractometer KWS-2 of the Jülich Centre for Neutron Science at the Heinz Maier-Leibnitz Center in Garching was equipped with a double-disc chopper with a variable opening slit window and time-of-flight (TOF) data acquisition option. The chopper used in concert with a dedicated high-intensity velocity selector enables the tuning at will of the wavelength resolution Δλ/λ within a broad range, from 20% (standard) down to 2%, in a convenient and safe manner following pre-planned or spontaneous decisions during the experiment. The new working mode is described in detail, and its efficiency is demonstrated on several standard samples with known properties and on a completely new crystallizable copolymer system, which were investigated using both the conventional (static) and TOF modes.

Performance and characteristics of the BILBY time-of-flight small-angle neutron scattering instrument

2019 ◽  
Vol 52 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Anna Sokolova ◽  
Andrew E. Whitten ◽  
Liliana de Campo ◽  
Jason Christoforidis ◽  
Andrew Eltobaji ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Materials Science ◽  
Time Of Flight ◽  
Nuclear Science ◽  
Scientific Disciplines ◽  
Wide Range ◽  
Wavelength Resolution ◽  
Reference Samples

BILBY is a recently constructed and commissioned time-of-flight small-angle neutron scattering instrument, operated by the Australian Centre for Neutron Scattering at the Australian Nuclear Science and Technology Organisation (ANSTO). BILBY provides a wide accessible q range (q ≃ 1.0 × 10−3 Å−1 to ∼1.8 Å−1) and variable wavelength resolution (Δλ/λ ≃ 3–30%) to complement the other small-angle and ultra-small-angle neutron scattering capabilities available at ANSTO. Since its construction, BILBY has been used to study samples from a wide range of scientific disciplines, including biology, chemistry, physics and materials science. This article describes the BILBY design and components, and shows data collected from a number of reference samples.

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.

scholarly journals The impact of radical loading and oxidation on the conformation of organic radical polymers by small angle neutron scattering

2018 ◽  
Vol 6 (32) ◽  
pp. 15659-15667 ◽  
Author(s):  
Halie J. Martin ◽  
Barbara K. Hughes ◽  
Wade A. Braunecker ◽  
Thomas Gennett ◽  
Mark D. Dadmun
Keyword(s):  
Molecular Structure ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Organic Radical ◽  
The Impact ◽  
First Time ◽  
Insight Into

SANS provides, for the first time, unique insight into the correlation between organic radical polymer molecular structure and their assembly.

Light-induced structural evolution of photoswitchable carbohydrate-based surfactant micelles

2015 ◽  
Vol 51 (25) ◽  
pp. 5509-5512 ◽  
Author(s):  
Rico F. Tabor ◽  
Matthew J. Pottage ◽  
Christopher J. Garvey ◽  
Brendan L. Wilkinson
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Structural Changes ◽  
Structural Evolution ◽  
Time Resolved ◽  
Surfactant Micelles ◽  
First Time ◽  
Over Time

We report the light-induced structural evolution of photoswitchable carbohydrate-based surfactant micelles using time-resolved small-angle neutron scattering (TR-SANS), monitoring the structural changes in micellisation in situ over time and demonstrating for the first time the course and implications of this process.

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 Small-angle neutron scattering solution structures of NADPH-dependent sulfite reductase

2020 ◽  
Author(s):  
Daniel T Murray ◽  
Kevin Weiss ◽  
Christopher B Stanley ◽  
Gergely Nagy ◽  
M. Elizabeth Stroupe
Keyword(s):  
Electron Transfer ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Single Copy ◽  
Sulfite Reductase ◽  
Solution Structures ◽  
Contrast Matching ◽  
First Time ◽  
Binding Position

Sulfite reductase (SiR), a dodecameric complex of flavoprotein reductase subunits (SiRFP) and hemoprotein oxidase subunits (SiRHP), reduces sulfur reduction for biomass incorporation. Electron transfer within SiR requires intra- and inter-subunit interactions that are mediated by the relative position of each protein, governed by flexible domain movements. Using small-angle neutron scattering, we report the first solution structures of SiR heterodimers containing a single copy of each subunit. These structures show how the subunits bind and how both subunit binding and oxidation state impact SiRFP's conformation. Neutron contrast matching experiments on selectively deuterated heterodimers allow us to define the contribution of each subunit to the solution scattering. SiRHP binding induces a change in the position of SiRFP's flavodoxin-like domain relative to its ferredoxin-NADP+ reductase domain while compacting SiRHP's N-terminus. Reduction of SiRFP leads to a more open structure relative to its oxidized state, re-positioning SiRFP's N-terminal flavodoxin-like domain towards the SiRHP binding position. These structures show, for the first time, how both SiRHP binding to, and reduction of, SiRFP positions SiRFP for electron transfer between the subunits.

Butterfly Patterns: an Anomaly Common to the Neutron Scattering Spectra of Elongated Rubbers, Melts and Gels:

1991 ◽  
Vol 248 ◽  
Author(s):  
J. Bastide ◽  
F. Boue ◽  
R. Oeser ◽  
E. Mendes ◽  
F. Zielinski ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Proportion ◽  
Small Angle Neutron Scattering ◽  
Scattered Intensity ◽  
Extension Ratio ◽  
Scattering Spectra ◽  
First Time ◽  
Direction Opposite ◽  
Q Values

AbstractA totally unexpected phenomenon has been observed for the first time a few years ago when studying, by small angle neutron scattering, rubbery networks containing a small proportion of uncrosslinked labelled (deuterated) chains [1].When such a system is elongated, the scattered intensity strongly increases with the extension ratio λ for q vectors parallel to the stretching direction (and for low q values). Conversely, in the direction perpendicular to the elongation axis, the scattered intensity slightly decreases at low q for small extension ratios and then remains approximately constant when λ is further increased. The changes which are observed occur therefore in a direction opposite to the “conventional” one, i.e. that corresponding to chains effectively linked by at least two chemical junctions to the network and thus oriented on an average along the direction of stretching.

KWS-1 high-resolution small-angle neutron scattering instrument at JCNS: current state

2015 ◽  
Vol 48 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Artem V. Feoktystov ◽  
Henrich Frielinghaus ◽  
Zhenyu Di ◽  
Sebastian Jaksch ◽  
Vitaliy Pipich ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Grazing Incidence ◽  
Current State ◽  
Sample Position ◽  
Heavy Loads ◽  
First Time

The KWS-1 small-angle neutron scattering (SANS) instrument operated by the Jülich Centre for Neutron Science (JCNS) at the research reactor FRM II of the Heinz Maier-Leibnitz Zentrum in Garching near Munich has been recently upgraded. The KWS-1 instrument was updated, from its active collimation apertures to the detector cabling. Most of the parts of the instrument were installed for the first time, including a broadband polarizer, a large-cross-section radio-frequency spin flipper, a chopper and neutron lenses. A custom-designed hexapod in the sample position allows heavy loads and precise sample positioning in the beam for conventional SANS experiments as well as for grazing-incidence SANS under applied magnetic field. With the foreseenin situpolarization analysis the main scientific topic of the instrument tends towards magnetism. The performance of the polarizer and flipper was checked with a polarized3He cell at the sample position. The results of these checks and a comparison of test measurements on a ferrofluid in a magnetic field with polarized and nonpolarized neutrons are presented.

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