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Bouwman WG. Spin-echo small-angle neutron scattering for multiscale structure analysis of food materials. FOOD STRUCTURE 2021. [DOI: 10.1016/j.foostr.2021.100235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Kuhn SJ, Geerits N, Franz C, Plomp J, Dalgliesh RM, Parnell SR. Time-of-flight modulated intensity small-angle neutron scattering measurement of the self-diffusion constant of water. J Appl Crystallogr 2021. [DOI: 10.1107/s1600576721002612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The modulated intensity by zero effort small-angle neutron scattering (MI-SANS) technique is used to measure scattering with a high energy resolution on samples normally ill-suited for neutron resonance spin echo. The self-diffusion constant of water is measured over a q–t range of 0.01–0.2 Å−1 and 70–500 ps. In addition to demonstrating the methodology of using time-of-flight MI-SANS instruments to observe diffusion in liquids, the results support previous measurements on water performed with different methods. This polarized neutron technique simultaneously measures the intermediate scattering function for a wide range of time and length scales. Two radio frequency flippers were used in a spin-echo setup with a 100 kHz frequency difference in order to create a high-resolution time measurement. The results are compared with self-diffusion measurements made by other techniques and the general applicability of MI-SANS at a pulsed source is assessed.
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Bouwman WG, Knudsen EB, Udby L, Willendrup P. Simulations of foil-based spin-echo (modulated) small-angle neutron scattering with a sample using McStas. J Appl Crystallogr 2021; 54:195-202. [PMID: 33833647 PMCID: PMC7941320 DOI: 10.1107/s1600576720015496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/23/2020] [Indexed: 11/12/2023] Open
Abstract
For the further development of spin-echo techniques to label elastic scattering it is necessary to perform simulations of the Larmor precession of neutron spins in a magnetic field. The details of some of these techniques as implemented at the reactor in Delft are simulated. First, the workings of the magnetized foil flipper are simulated. A full virtual spin-echo small-angle neutron scattering instrument is built and tested without and with a realistic scattering sample. It is essential for these simulations to have a simulated sample that also describes the transmitted beam of unscattered neutrons, which usually is not implemented for the simulation of conventional small-angle neutron scattering (SANS) instruments. Finally, the workings of a spin-echo modulated small-angle neutron scattering (SEMSANS) instrument are simulated. The simulations are in good agreement with theory and experiments. This setup can be extended to include realistic magnetic field distributions to fully predict the features of future Larmor labelling elastic-scattering instruments. Configurations can now be simulated for more complicated combinations of SANS with SEMSANS.
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Bakker JH, Washington AL, Parnell SR, van Well AA, Pappas C, Bouwman WG. Analysis of SESANS data by numerical Hankel transform implementation in SasView. JOURNAL OF NEUTRON RESEARCH 2020. [DOI: 10.3233/jnr-200154] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Jurrian H. Bakker
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Adam L. Washington
- ISIS, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, United Kingdom
| | - Steven R. Parnell
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Ad A. van Well
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Catherine Pappas
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
| | - Wim G. Bouwman
- Radiation Science and Technology, Faculty of Applied Sciences, Delft University of Technology, Netherlands
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Bernardo G, Melle-Franco M, Washington AL, Dalgliesh RM, Li F, Mendes A, Parnell SR. Different agglomeration properties of PC61BM and PC71BM in photovoltaic inks – a spin-echo SANS study. RSC Adv 2020; 10:4512-4520. [PMID: 35495220 PMCID: PMC9049156 DOI: 10.1039/c9ra08019h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 12/10/2019] [Indexed: 11/21/2022] Open
Abstract
Fullerene derivatives are used in a wide range of applications including as electron acceptors in solution-processable organic photovoltaics.
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Affiliation(s)
- Gabriel Bernardo
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy
- Faculty of Engineering
- University of Porto
- 4200-465 Porto
- Portugal
| | - Manuel Melle-Franco
- CICECO—Aveiro Institute of Materials
- Department of Chemistry
- University of Aveiro
- 3810-193 Aveiro
- Portugal
| | - Adam L. Washington
- ISIS Pulsed Neutron and Muon Source
- STFC
- Rutherford Appleton Laboratory
- Oxon
- UK
| | | | - Fankang Li
- Neutron Technologies Division
- Oak Ridge National Laboratory
- Oak Ridge
- USA
| | - Adélio Mendes
- LEPABE – Laboratory for Process Engineering, Environment, Biotechnology and Energy
- Faculty of Engineering
- University of Porto
- 4200-465 Porto
- Portugal
| | - Steven R. Parnell
- Faculty of Applied Sciences
- Delft University of Technology
- 2629 JB Delft
- Netherlands
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Li F, Shen J, Parnell SR, Thaler AN, Matsuda M, Keller T, Delaire O, Pynn R, Fernandez-Baca JA. High-resolution phonon energy shift measurements with the inelastic neutron spin echo technique. J Appl Crystallogr 2019. [DOI: 10.1107/s1600576719008008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The energy resolution of the conventional way of measuring a small change in a phonon dispersion curve using neutron scattering is restricted by the relatively coarse intrinsic resolution ellipsoid of the neutron triple-axis spectrometer (TAS). By implementing inelastic neutron spin echo on the host TAS using the Larmor precession of the neutron spin, the energy resolution of such measurements can be further improved without reducing the resolution ellipsoid. Measurements of the temperature-dependent phonon energy change are demonstrated using superconducting magnetic Wollaston prisms at the HB-1 instrument of the High-Flux Isotope Reactor at Oak Ridge National Laboratory, and the achievable resolution is <10 µeV.
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Li F, Parnell SR, Dalgliesh R, Washington A, Plomp J, Pynn R. Data Correction of Intensity Modulated Small Angle Scattering. Sci Rep 2019; 9:8563. [PMID: 31189935 PMCID: PMC6561909 DOI: 10.1038/s41598-019-44493-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 04/25/2019] [Indexed: 11/29/2022] Open
Abstract
To investigate long length scale structures using neutron scattering, real space techniques have shown certain advantages over the conventional methods working in reciprocal space. As one of the real space measurement techniques, spin echo modulated small angle neutron scattering (SEMSANS) has attracted attention, due to its relaxed constraints on sample environment and the possibility to combine SEMSANS and a conventional small angle neutron scattering instrument. In this report, we present the first implementation of SEMSANS at a pulsed neutron source and discuss important corrections to the data due to the sample absorption. These corrections allow measurements made with different neutron wavelengths and SEMSANS configurations to be overlaid and give confidence that the measurements provide an accurate representation of the density correlations in the sample.
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Affiliation(s)
- Fankang Li
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.
| | - Steven R Parnell
- Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, Delft, JB 2629, The Netherlands
| | - Robert Dalgliesh
- ISIS Pulsed Neutron and Muon Source, STFC, Rutherford Appleton Laboratory, Chilton, Oxon, OX11 0QX, UK
| | - Adam Washington
- ISIS Pulsed Neutron and Muon Source, STFC, Rutherford Appleton Laboratory, Chilton, Oxon, OX11 0QX, UK
| | - Jeroen Plomp
- Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, Delft, JB 2629, The Netherlands
| | - Roger Pynn
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA.,Center for Exploration of Energy and Matter, Indiana University, Bloomington, IN, 47408, USA
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Li F, Feng H, Thaler AN, Parnell SR, Crow L, Matsuda M, Ye F, Kimura T, Fernandez-Baca JA, Pynn R. New capabilities in high-resolution neutron Larmor diffraction at ORNL. J Appl Crystallogr 2018. [DOI: 10.1107/s1600576718004211] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Using superconducting magnetic Wollaston prisms, high-resolution neutron Larmor diffraction has been implemented at the High-Flux Isotope Reactor of Oak Ridge National Laboratory (ORNL), Tennesse, USA. This technique allows the inverse relationship between the achievable diffraction resolution and the usable neutron flux to be overcome. Instead of employing physically tilted radio-frequency spin flippers, the method uses magnetic Wollaston prisms which are electromagnetically tuned by changing the field configurations in the device. As implemented, this method can be used to measure lattice-spacing changes induced, for example, by thermal expansion or strain with a resolution of Δd/d ≃ 10−6, and the splitting of sharp Bragg peaks with a resolution of Δd/d = 3 × 10−4. The resolution for discerning a change in the profile of a Bragg peak is Δd/d < 10−5. This is a remarkable degree of precision for a neutron diffractometer as compact as the one used in this implementation. Higher precision could be obtained by implementing this technique in an instrument with a larger footprint. The availability of this technique will provide an alternative when standard neutron diffraction methods fail and will greatly benefit the scientific communities that require high-resolution diffraction measurements.
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Abstract
This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements.
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Affiliation(s)
- T. R. Gentile
- National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, USA
| | - P. J. Nacher
- Laboratoire Kastler Brossel, ENS-PSL Research University, CNRS, UPMC-Sorbonne Universités, Collège de France, Paris, France
| | - B. Saam
- Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA
| | - T. G. Walker
- Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
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Jiang CY, Tong X, Brown DR, Glavic A, Ambaye H, Goyette R, Hoffmann M, Parizzi AA, Robertson L, Lauter V. New generation high performance in situ polarized 3He system for time-of-flight beam at spallation sources. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:025111. [PMID: 28249509 DOI: 10.1063/1.4975991] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Modern spallation neutron sources generate high intensity neutron beams with a broad wavelength band applied to exploring new nano- and meso-scale materials from a few atomic monolayers thick to complicated prototype device-like systems with multiple buried interfaces. The availability of high performance neutron polarizers and analyzers in neutron scattering experiments is vital for understanding magnetism in systems with novel functionalities. We report the development of a new generation of the in situ polarized 3He neutron polarization analyzer for the Magnetism Reflectometer at the Spallation Neutron Source at Oak Ridge National Laboratory. With a new optical layout and laser system, the 3He polarization reached and maintained 84% as compared to 76% in the first-generation system. The polarization improvement allows achieving the transmission function varying from 50% to 15% for the polarized neutron beam with the wavelength band of 2-9 Angstroms. This achievement brings a new class of experiments with optimal performance in sensitivity to very small magnetic moments in nano systems and opens up the horizon for its applications.
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Affiliation(s)
- C Y Jiang
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - X Tong
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - D R Brown
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - A Glavic
- Quantum Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - H Ambaye
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - R Goyette
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - M Hoffmann
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - A A Parizzi
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - L Robertson
- Instrument and Source Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - V Lauter
- Quantum Condensed Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
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Ino T, Hayashida H, Kira H, Oku T, Sakai K. Non-magnetic flexible heaters for spin-exchange optical pumping of 3He and other applications. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:115108. [PMID: 27910610 DOI: 10.1063/1.4967527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Spin polarized 3He gas is currently widely used in various scientific fields and in medical diagnosis applications. The spin polarization of 3He nuclei can be achieved by spin-exchange optical pumping (SEOP). In SEOP, the 3He gas is enclosed in a glass cell together with alkali metals and is then heated to maintain the alkali metal vapor pressures at the appropriate levels. However, polarized 3He gas is highly sensitive to any inhomogeneity in its magnetic field, and any small field gradients caused by the heaters may cause degradation of the 3He polarization. To overcome this conflict between the heating process and the magnetic field, we have developed electrical heaters that essentially cause no magnetic fields. These heaters are thin and are flexible enough to be bent to within a radius of a few centimeters. These carefully designed heater elements and a double layer structure effectively eliminate magnetic field generation. The heaters were originally developed for SEOP applications, but can also be applied to other processes that need to avoid unwanted magnetic fields.
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Affiliation(s)
- T Ino
- IMSS, KEK, Tsukuba, Ibaraki 305-0801, Japan
| | | | - H Kira
- CROSS, Tokai, Ibaraki 319-1106, Japan
| | - T Oku
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
| | - K Sakai
- J-PARC Center, Tokai, Ibaraki 319-1195, Japan
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Parnell SR, Washington AL, Parnell AJ, Walsh A, Dalgliesh RM, Li F, Hamilton WA, Prevost S, Fairclough JPA, Pynn R. Porosity of silica Stöber particles determined by spin-echo small angle neutron scattering. SOFT MATTER 2016; 12:4709-14. [PMID: 27021920 DOI: 10.1039/c5sm02772a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Stöber silica particles are used in a diverse range of applications. Despite their widespread industrial and scientific uses, information on the internal structure of the particles is non-trivial to obtain and is not often reported. In this work we have used spin-echo small angle neutron scattering (SESANS) in conjunction with ultra small angle X-ray scattering (USAXS) and pycnometry to study an aqueous dispersion of Stöber particles. Our results are in agreement with models which propose that Stöber particles have a porous core, with a significant fraction of the pores inaccessible to solvent. For samples prepared from the same master sample in a range of H2O : D2O ratio solutions we were able to model the SESANS results for the solution series assuming monodisperse, smooth surfaced spheres of radius 83 nm with an internal open pore volume fraction of 32% and a closed pore fraction of 10%. Our results are consistent with USAXS measurements. The protocol developed and discussed here shows that the SESANS technique is a powerful way to investigate particles much larger than those studied using conventional small angle scattering methods.
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Affiliation(s)
- S R Parnell
- Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands. and Centre for Exploration of Energy and Matter, Indiana University, Bloomington, 47408, USA
| | - A L Washington
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK and Department of Mechanical Engineering, The University of Sheffield, Sheffield, S1 3DJ, UK
| | - A J Parnell
- Department of Physics and Astronomy, The University of Sheffield, Sheffield, S3 7RH, UK
| | - A Walsh
- Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK
| | - R M Dalgliesh
- ISIS, Rutherford Appleton Laboratory, Chilton, Oxfordshire, OX11 0QX, UK
| | - F Li
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, 47408, USA
| | - W A Hamilton
- Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, 37831, USA
| | - S Prevost
- ID02 Beamline, European Synchrotron Radiation Facility, F38043, Grenoble, France
| | - J P A Fairclough
- Department of Mechanical Engineering, The University of Sheffield, Sheffield, S1 3DJ, UK
| | - R Pynn
- Centre for Exploration of Energy and Matter, Indiana University, Bloomington, 47408, USA and Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, 37831, USA
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Wang T, Parnell SR, Hamilton WA, Li F, Washington AL, Baxter DV, Pynn R. Compact spherical neutron polarimeter using high-T(c) YBCO films. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:033901. [PMID: 27036785 DOI: 10.1063/1.4943254] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/20/2016] [Indexed: 06/05/2023]
Abstract
We describe a simple, compact device for spherical neutron polarimetry measurements at small neutron scattering angles. The device consists of a sample chamber with very low (<0.01 G) magnetic field flanked by regions within which the neutron polarization can be manipulated in a controlled manner. This allows any selected initial and final polarization direction of the neutrons to be obtained. We have constructed a prototype device using high-T(c) superconducting films and mu-metal to isolate regions with different magnetic fields and tested device performance in transmission geometry. Finite-element methods were used to simulate the device's field profile and these have been verified by experiment using a small solenoid as a test sample. Measurements are reported using both monochromatic and polychromatic neutron sources. The results show that the device is capable of extracting sample information and distinguishing small angular variations of the sample magnetic field. As a more realistic test, we present results on the characterization of a 10 μm thick Permalloy film in zero magnetic field, as well as its response to an external magnetic field.
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Affiliation(s)
- T Wang
- Center for Exploration of Energy and Matter, Indiana University Bloomington, Bloomington, Indiana 47408, USA
| | - S R Parnell
- Center for Exploration of Energy and Matter, Indiana University Bloomington, Bloomington, Indiana 47408, USA
| | - W A Hamilton
- Neutron Science Directorate, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37381, USA
| | - F Li
- Center for Exploration of Energy and Matter, Indiana University Bloomington, Bloomington, Indiana 47408, USA
| | - A L Washington
- Department of Physics and Astronomy, The University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - D V Baxter
- Center for Exploration of Energy and Matter, Indiana University Bloomington, Bloomington, Indiana 47408, USA
| | - R Pynn
- Center for Exploration of Energy and Matter, Indiana University Bloomington, Bloomington, Indiana 47408, USA
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Li F, Parnell SR, Bai H, Yang W, Hamilton WA, Maranville BB, Ashkar R, Baxter DV, Cremer JT, Pynn R. Spin echo modulated small-angle neutron scattering using superconducting magnetic Wollaston prisms. J Appl Crystallogr 2016. [DOI: 10.1107/s1600576715021573] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The spin echo modulated small-angle neutron scattering technique has been implemented using two superconducting magnetic Wollaston prisms at a reactor neutron source. The density autocorrelation function measured for a test sample of colloidal silica in a suspension agrees with that obtained previously by other neutron scattering methods on an identically prepared sample. The reported apparatus has a number of advantages over competing technologies: it should allow larger length scales (up to several micrometres) to be probed; it has very small parasitic neutron scattering and attenuation; the magnetic fields within the device are highly uniform; and the neutron spin transport across the device boundaries is very efficient. To understand quantitatively the results of the reported experiment and to guide future instrument development, Monte Carlo simulations are presented, in which the evolution of the neutron polarization through the apparatus is based on magnetic field integrals obtained from finite-element simulations of the various magnetic components. The Monte Carlo simulations indicate that the polarization losses observed in the experiments are a result of instrumental artifacts that can be easily corrected in future experiments.
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