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12 pages, 3736 KB

Open AccessArticle

A Focusing Supermirror for Time-of-Flight Grazing-Incidence Small-Angle Neutron Scattering Measurement

by Dai Yamazaki, Ryuji Maruyama, Hiroyuki Aoki, Takayasu Hanashima, Kazuhiro Akutsu-Suyama, Noboru Miyata and Kazuhiko Soyama

Quantum Beam Sci. 2025, 9(2), 20; https://doi.org/10.3390/qubs9020020 - 10 Jun 2025

Viewed by 581

Abstract

This study developed a neutron-beam-focusing supermirror for grazing-incidence small-angle neutron scattering (GISANS) measurements. We adopted point-to-point beam focusing based on an ellipse whose two foci correspond to a virtual point source and a spot on the detector surface. The focusing supermirror was fabricated [...] Read more.

This study developed a neutron-beam-focusing supermirror for grazing-incidence small-angle neutron scattering (GISANS) measurements. We adopted point-to-point beam focusing based on an ellipse whose two foci correspond to a virtual point source and a spot on the detector surface. The focusing supermirror was fabricated by depositing NiC/Ti supermirror film with ion-beam sputtering on a precise elliptic surface of fused quartz figured using the elastic emission machining technique. Neutron measurements at the pulsed neutron reflectometer BL17 of the MLF, J-PARC, successfully demonstrated that the focusing supermirror enhances the beam intensity twentyfold compared with an optimally collimated beam, achieving a signal-to-background ratio of the focal spot as high as 500. The mirror can be readily installed and used at BL17 for time-of-flight GISANS measurements. Full article

(This article belongs to the Section Radiation Scattering Fundamentals and Theory)

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17 pages, 7356 KB

Open AccessArticle

A Comprehensive Error Analysis of the Neutron Elliptical Cylindrical Mirror with High Gain

by Weichen Gu, Jun Yu, Pengfeng Sheng, Fengrui Tang, Qiya Zhang, Peng Chen, Qiaoyu Wu, Wentao Song, Zhangran Cao, Zhengxiang Shen, Zhong Zhang and Zhanshan Wang

Photonics 2025, 12(6), 580; https://doi.org/10.3390/photonics12060580 - 6 Jun 2025

Viewed by 454

Abstract

The elliptical cylindrical mirror has been utilized in neutron small-angle scattering and reflectometry to enhance the neutron intensity at the sample position. However, the performance of the elliptical cylindrical mirror can be impacted by surface slope errors, reflectivity, and misalignments. In this work, [...] Read more.

The elliptical cylindrical mirror has been utilized in neutron small-angle scattering and reflectometry to enhance the neutron intensity at the sample position. However, the performance of the elliptical cylindrical mirror can be impacted by surface slope errors, reflectivity, and misalignments. In this work, the performance of the elliptical cylindrical mirror under different error conditions has been analyzed comprehensively, and a 250-mm-long elliptical cylindrical mirror was designed and developed. The simulations show that a source size below 1 mm is required to achieve a peak gain above 6, with a theoretical peak gain of 16× with a 0.1 mm source. The rotational misalignment of 0.03° around the Y-axis can decrease gain from 16× to 6×. The designed mirror was fabricated with a surface figure error of 110 nm (RMS), and a roughness below 0.5 nm (RMS), and was coated with an m = 4 supermirror. The mirror was aligned and tested in the dedicated neutron beamline of the Chinese mianyang research reactor, and the results show a peak gain of 12.77 with a 0.1 mm slit source. Full article

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12 pages, 4427 KB

Open AccessArticle

Microstructure Evolution in Magnetron-Sputtered WC/SiC Multilayers with Varied WC Layer Thicknesses

by Tongzhou Li, Zhe Zhang, Zile Wang, Li Jiang, Runze Qi, Qiushi Huang, Zhong Zhang and Zhanshan Wang

Coatings 2024, 14(6), 720; https://doi.org/10.3390/coatings14060720 - 5 Jun 2024

Cited by 3 | Viewed by 1468

Abstract

Owing to the superior quality of the interface, WC/SiC multilayers have been considered promising candidates for X-ray Laue lenses in nano-focusing facilities and supermirrors in X-ray telescopes. To investigate the microstructure evolution in WC/SiC multilayers, a set of periodic multilayers was prepared with [...] Read more.

Owing to the superior quality of the interface, WC/SiC multilayers have been considered promising candidates for X-ray Laue lenses in nano-focusing facilities and supermirrors in X-ray telescopes. To investigate the microstructure evolution in WC/SiC multilayers, a set of periodic multilayers was prepared with varied WC layer thicknesses ranging from 1.0 nm to 10.0 nm while keeping the thickness of the SiC layer constant at 3.0 nm. These samples were characterized using various analytical techniques, including GIXR, AFM, and XRD. An aperiodic WC/SiC multilayer sample was analyzed by TEM, EDX, and SAED to further study the chemical and structural changes while the thickness of the WC layer increased. The results indicate that the WC layer of the WC/SiC multilayer changes from amorphous to crystalline with increasing layer thickness. The crystalline state of the WC layer changes as the thickness increases. Meanwhile, the carbon atoms migrates noticeably to the interface as the WC layer becomes thicker, which smoothens the interfacial defects caused by the crystalline state transition. This migration of carbon is one of the key factors contributing to the smooth interface in WC/SiC multilayers. Full article

(This article belongs to the Section Surface Characterization, Deposition and Modification)

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16 pages, 11611 KB

Open AccessArticle

New Ballistic Neutron Guide for the Time-of-Flight Spectrometer FOCUS at PSI

by Fanni Juranyi, Masako Yamada, Christine Klauser, Lothar Holitzner and Uwe Filges

Quantum Beam Sci. 2024, 8(1), 8; https://doi.org/10.3390/qubs8010008 - 13 Feb 2024

Viewed by 2385

Abstract

FOCUS is a direct-geometry cold neutron time-of-flight spectrometer at SINQ (PSI, CH). Its neutron guide was exchanged in 2019/2020 within the SINQ Upgrade project, while the rest of the instrument remained unchanged. The new guide provided a significant intensity increase across the whole [...] Read more.

FOCUS is a direct-geometry cold neutron time-of-flight spectrometer at SINQ (PSI, CH). Its neutron guide was exchanged in 2019/2020 within the SINQ Upgrade project, while the rest of the instrument remained unchanged. The new guide provided a significant intensity increase across the whole spectrum, especially at short wavelengths, due to the more efficient transport and extended phase space of the transported neutrons. The practically available energy transfer range (at the neutron energy loss side) was increased to about 40 meV. The main reason for the intensity benefit at short incident wavelengths was the improved guide coating, whereas at long wavelengths it was the new ballistic shape. The interesting part of the guide is the “peanut shape” of the curved part in the horizontal plane. For this, we derived the analytical restriction on the geometry to avoid a direct line of sight from the source. The guide geometry and the supermirror coating were optimized using Mcoptimize, a particle swarm optimization routine employing Mcstas. Future ballistic neutron guides may profit from the presented approaches, optimization strategy, and results. Full article

(This article belongs to the Special Issue New Trends in Neutron Instrumentation, 2nd Edition)

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14 pages, 2542 KB

Open AccessArticle

Crystallization and Composition of Ni-C/Ti Multilayer with Varied Ni-C Thickness

by Qiya Zhang, Zhong Zhang, Yang Liu and Zhanshan Wang

Coatings 2022, 12(8), 1144; https://doi.org/10.3390/coatings12081144 - 8 Aug 2022

Cited by 4 | Viewed by 2156

Abstract

Ni-C/Ti are suitable for the components of neutron supermirrors with high reflectivity because of their excellent optical constant and smoother interfaces compared to Ni/Ti. In this paper, to investigate the mechanism of C doping to the interface, crystallization, and composition of a Ni-C/Ti [...] Read more.

Ni-C/Ti are suitable for the components of neutron supermirrors with high reflectivity because of their excellent optical constant and smoother interfaces compared to Ni/Ti. In this paper, to investigate the mechanism of C doping to the interface, crystallization, and composition of a Ni-C/Ti multilayer with variable Ni-C thickness, four Ni-C/Ti multilayers were prepared by direct current magnetron sputtering, in which the thickness of the Ni-C layers was 1.5 nm, 2.5 nm, 3.5 nm, and 4.5 nm, respectively, and the thickness of the Ti layers was kept at 5 nm. The prepared samples were characterized by XRD, XPS, HRTEM, EDX, and SAED. The XRD and HRTEM results show that Ni-C layers in Ni-C/Ti multilayers translate from amorphous to polycrystal form, with their thickness increasing from 1.5 to 4.5 nm, and the crystallite size in Ni-C layers is equivalent to the layer thickness, respectively. The XPS, SAED, and EDX results illustrate that the enrichment position of C in Ni-C/Ti multilayers evolves from the Ni-C layers to the Ti layers as the respective Ni-C layer thickness increases from 2.5 to 4.5 nm. The enrichment position evolution of C in Ni-C/Ti multilayers could be due to the lower standard Gibbs free energy of TiC (−180.1 KJ/mol) compared with NiTi (−37.3 KJ/mol) and Ni3Ti (−35.9 KJ/mol) at 298 K. Full article

(This article belongs to the Section Corrosion, Wear and Erosion)

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12 pages, 3008 KB

Open AccessArticle

First Experiment of Spin Contrast Variation Small-Angle Neutron Scattering on the iMATERIA Instrument at J-PARC

by Yohei Noda, Tomoki Maeda, Takayuki Oku, Satoshi Koizumi, Tomomi Masui and Hiroyuki Kishimoto

Quantum Beam Sci. 2020, 4(4), 33; https://doi.org/10.3390/qubs4040033 - 25 Sep 2020

Cited by 9 | Viewed by 3665

Abstract

Recently, we have developed a novel dynamic nuclear polarization (DNP) apparatus with a magnetic field of 7 T and a sample temperature of 1 K. High proton spin polarizations from −84% to 76%, for TEMPO doped polystyrene samples, have been demonstrated. This DNP [...] Read more.

Recently, we have developed a novel dynamic nuclear polarization (DNP) apparatus with a magnetic field of 7 T and a sample temperature of 1 K. High proton spin polarizations from −84% to 76%, for TEMPO doped polystyrene samples, have been demonstrated. This DNP apparatus satisfies the simultaneous requirement for quick and easy sample exchange and high DNP performance. On the iMATERIA (BL20) instrument at J-PARC, the first beam experiment using this DNP apparatus has been performed. For this experiment, the beamline was equipped with a supermirror polarizer. The stray magnetic field due to the superconducting magnet for DNP was also evaluated. The stray magnetic field plays an important role for in maintaining the neutron polarization during the transportation from the polarizer to the sample. The small-angle neutron scattering (SANS) profiles of silica-filled rubber under dynamically polarized conditions are presented. By applying our new analytical approach for SANS coherent scattering intensity, neutron polarization (P_N) as a function of neutron wavelength was determined. Consequently, for the neutron wavelength, range from 4 Å to 10 Å, |P_N| was sufficient for DNP-SANS studies. Full article

(This article belongs to the Special Issue New Trends in Neutron Instrumentation)

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35 pages, 11793 KB

Open AccessReview

Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex III: Neutron Devices and Computational and Sample Environments

by Kaoru Sakasai, Setsuo Satoh, Tomohiro Seya, Tatsuya Nakamura, Kentaro Toh, Hideshi Yamagishi, Kazuhiko Soyama, Dai Yamazaki, Ryuji Maruyama, Takayuki Oku, Takashi Ino, Hiroshi Kira, Hirotoshi Hayashida, Kenji Sakai, Shinichi Itoh, Kentaro Suzuya, Wataru Kambara, Ryoichi Kajimoto, Kenji Nakajima, Kaoru Shibata, Mitsutaka Nakamura, Toshiya Otomo, Takeshi Nakatani, Yasuhiro Inamura, Jiro Suzuki, Takayoshi Ito, Nobuo Okazaki, Kentaro Moriyama, Kazuya Aizawa, Seiko Ohira-Kawamura and Masao Watanabe Show full author list Hide full author list

Quantum Beam Sci. 2017, 1(2), 10; https://doi.org/10.3390/qubs1020010 - 3 Aug 2017

Cited by 17 | Viewed by 7571

Abstract

Neutron devices such as neutron detectors, optical devices including supermirror devices and ³He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software [...] Read more.

Neutron devices such as neutron detectors, optical devices including supermirror devices and ³He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF. Full article

(This article belongs to the Collection Facilities)

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14 pages, 174 KB

Open AccessCommunication

Application of Diamond Nanoparticles in Low-Energy Neutron Physics

by Valery Nesvizhevsky, Robert Cubitt, Egor Lychagin, Alexei Muzychka, Grigory Nekhaev, Guillaume Pignol, Konstantin Protasov and Alexander Strelkov

Materials 2010, 3(3), 1768-1781; https://doi.org/10.3390/ma3031768 - 10 Mar 2010

Cited by 34 | Viewed by 14804

Abstract

Diamond, with its exceptionally high optical nuclear potential and low absorption cross-section, is a unique material for a series of applications in VCN (very cold neutron) physics and techniques. In particular, powder of diamond nanoparticles provides the best reflector for neutrons in the [...] Read more.

Diamond, with its exceptionally high optical nuclear potential and low absorption cross-section, is a unique material for a series of applications in VCN (very cold neutron) physics and techniques. In particular, powder of diamond nanoparticles provides the best reflector for neutrons in the complete VCN energy range. It allowed also the first observation of quasi-specular reflection of cold neutrons (CN) from disordered medium. Effective critical velocity for such a quasi-specular reflection is higher than that for the best super-mirror. Nano-diamonds survive in high radiation fluxes; therefore they could be used, under certain conditions, in the vicinity of intense neutron sources. Full article

(This article belongs to the Special Issue The New Diamond Age?)

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