Design of a neutron microscope based on Wolter mirrors

Hussey, Daniel S.; Abir, Muhammad; Cook, J.C.; Jacobson, David L.; LaManna, Jacob M.; Kilaru, Kiranmayee; Ramsey, Brian D.; Khaykovich, Boris

doi:10.1016/j.nima.2020.164813

Cited by 9 publications

(3 citation statements)

References 21 publications

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“…While beyond the scope of this paper, several additional approaches may further enhance this technique. Ongoing efforts to improve the resolution and sensitivity of neutron imaging (Hussey et al., 2021; Trtik et al., 2015) will make the neutron data more comparable to those obtained using X‐rays, and correlation and addition of results from neutron Bragg‐edge imaging (Vitucci et al., 2018) may add a third variable, correlated with large crystal structure or potentially strain in the sample, to results from neutron and X‐ray attenuation. In addition, the histogram‐based segmentation techniques employed here, while sufficient for the purposes of this paper, can be enhanced to better separate the various phases involved, in part by taking advantage of their three‐dimensional spatial associations, using one or more cluster analysis techniques (e.g., K‐means, K‐medians, mean shift, density‐based spatial clustering of applications with noise, expectation–maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering).…”

Section: Discussionmentioning

confidence: 99%

Coordinated neutron and X‐ray computed tomography of meteorites: Detection and distribution of hydrogen‐bearing materials

Treiman

LaManna

Hussey

et al. 2022

Meteorit & Planetary Scien

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The presence and distribution of hydrogen-bearing materials in meteorites are important constraints on processes in the early solar system, and the delivery of volatile constituents to growing planets. Here, we show that coordinated neutron and X-ray computed tomography, NXCT, can reveal the presence and distributions of hydrogenbearing materials in meteorites, and thus help constrain the presence and actions of water in the early solar system. NXCT is nearly nondestructive of meteorite samples. Neutron fluence in NXCT is approximately seven orders of magnitude less than in typical instrumental neutron activation analysis, and so produces little residual radioactivity and currently undetectable changes in isotope ratios. Heating during NXCT is minimal, but NXCT will overprint the record of cosmic ray exposure held in natural thermoluminescence. Two meteorites were examined. EET 87503 is a howardite, a regolith breccia inferred to be from the asteroid 4 Vesta, and contains fragments of eucrite basalt, diogenite pyroxenite, and H-rich carbonaceous chondrites. With NXCT, the chondrite fragments within the meteorite piece can be clearly located and characterized, in preparation for possible extraction and detailed analyses. Graves Nunataks (GRA) 06100 is a CR2 chondrite meteorite that contains abundant iron metal and H-bearing silicates from aqueous alteration. In NXCT, H-bearing altered material is clearly distinguished from metal, and its distribution in three dimensions is revealed as a constraint on the processes of alteration.

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Section: Discussionmentioning

confidence: 99%

Coordinated neutron and X‐ray computed tomography of meteorites: Detection and distribution of hydrogen‐bearing materials

Treiman

LaManna

Hussey

et al. 2022

Meteorit & Planetary Scien

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“…Novel lens systems for neutrons promise gains of the order of 10 4 [91], and long wavelengths are advantageous for lenses due to the refractive index increasing with λ 2 , the focal length increasing with λ −2 , and the critical angle proportional to λ. The concern about increased absorption makes reflective focusing optics, like Wolter optics [130], a very attractive choice, and, by using shorter focal lengths, the impact of gravity can be minimized.…”

Section: Vcns In Condensed Matter Researchmentioning

confidence: 99%

HighNESS conceptual design report: Volume I

Santoro,

Abou El Kheir,

Acharya

et al. 2024

JNR

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The European Spallation Source, currently under construction in Lund, Sweden, is a multidisciplinary international laboratory. Once completed to full specifications, it will operate the world’s most powerful pulsed neutron source. Supported by a 3 million Euro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) has been completed to develop a second neutron source located below the spallation target. Compared to the first source, designed for high cold and thermal brightness, the new source has been optimized to deliver higher intensity, and a shift to longer wavelengths in the spectral regions of cold (CN, 2–20 Å), very cold (VCN, 10–120 Å), and ultracold (UCN, >500 Å) neutrons. The second source comprises a large liquid deuterium moderator designed to produce CN and support secondary VCN and UCN sources. Various options have been explored in the proposed designs, aiming for world-leading performance in neutronics. These designs will enable the development of several new instrument concepts and facilitate the implementation of a high-sensitivity neutron-antineutron oscillation experiment (NNBAR). This document serves as the Conceptual Design Report for the HighNESS project, representing its final deliverable.

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“…Among reflected focusing optics, Kirkpatrick-Baez (Ice et al, 2005(Ice et al, , 2006 and Montel (Ice et al, 2009) mirrors have a small geometric collecting area of the order of a square millimetre in the azimuth. Fully annular ellipsoidal and Wolter mirrors have a structural advantage that significantly enhances the neutron flux by tens of times or even more (Khaykovich et al, 2011;Mildner & Gubarev, 2011;Takeda et al, 2018;Hussey et al, 2021). Ellipsoidal mirrors have a higher reflection efficiency due to their single reflections, while Wolter mirrors can achieve a shorter focusing distance and eliminate the severe coma of ellipsoidal mirrors.…”

Section: Introductionmentioning

confidence: 99%

Design of multi-shell nested fully annular quasi-ellipsoidal focusing mirrors for small-angle neutron scattering

Song,

Zhang,

Zhang

et al. 2023

J Appl Cryst

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The neutron flux is a crucial factor for neutron scattering measurements, especially for compact sources. Among various neutron optics, grazing-incidence focusing mirrors have been developed to give a significant increase in the neutron flux on a sample owing to their great potential for collecting neutrons in small-angle neutron scattering (SANS) instruments. Focusing mirrors with a supermirror coating can be nested to collect a neutron beam with large divergence. Nested conical integrated assembly technology is employed to manufacture nested focusing mirrors. This study describes the design of ten-shell nested fully annular quasi-ellipsoidal focusing mirrors with an m = 3 Ni/Ti supermirror coating to produce enough neutrons on a sample under the premise of satisfying the specified minimum wavevector transfer Q. For fully annular focusing mirrors, the neutron current received by a sample from the entire annular focusing neutron beam is more relevant. A ray-tracing method and current gain calculation are used to evaluate the performance of the designed mirrors. The ray-tracing result shows that the ideal resolution of quasi-ellipsoidal mirrors with four-segment conical approximation is 1.354 mm. As the source radius decreases from 20 mm, the neutron current with the designed focusing mirrors can be enhanced by a factor of 13 to over 100 compared with that without focusing mirrors in the same detected area. The effective collecting area is 186 cm2 when the source radius is the optimal 15 mm. An 83-fold current gain can be obtained for cold neutrons. The proposed mirrors can reach 90.7 and 87.3% of the maximum current of the corresponding optimal mirror structure when the source radii are 10 and 20 mm, respectively. The results demonstrate that the proposed mirrors are adaptable for instruments with changeable sources.

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Design of a neutron microscope based on Wolter mirrors

Cited by 9 publications

References 21 publications

Coordinated neutron and X‐ray computed tomography of meteorites: Detection and distribution of hydrogen‐bearing materials

Coordinated neutron and X‐ray computed tomography of meteorites: Detection and distribution of hydrogen‐bearing materials

HighNESS conceptual design report: Volume I

Design of multi-shell nested fully annular quasi-ellipsoidal focusing mirrors for small-angle neutron scattering

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