The coherent radiation fraction of low-emittance synchrotrons

Westfahl, Harry; Luiz, Sergio A. L.; Meyer, Bernd; Meneau, Florian

doi:10.1107/s1600577517003058

Cited by 12 publications

(10 citation statements)

References 24 publications

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“…In contrast with the third generation, the fourth-generation synchrotrons, also called the fourth generation, are very low emittance machines (order of 200 pm·rad), − leading to an ultrabrilliant and coherent source. Hence, exploiting an optics that preserves the coherent flux from the source, a full coherent beam can be focused on the sample with a coherent photon flux 10 2 to 10 4 times higher than that obtained in the third-generation synchrotrons.…”

Section: Fundamental Aspects Of Bcdimentioning

confidence: 99%

Bragg Coherent Diffraction Imaging for In Situ Studies in Electrocatalysis

et al. 2021

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Electrocatalysis is at the heart of a broad range of physicochemical applications that play an important role in the present and future of a sustainable economy. Among the myriad of different electrocatalysts used in this field, nanomaterials are of ubiquitous importance. An increased surface area/volume ratio compared to bulk makes nanoscale catalysts the preferred choice to perform electrocatalytic reactions. Bragg coherent diffraction imaging (BCDI) was introduced in 2006 and since has been applied to obtain 3D images of crystalline nanomaterials. BCDI provides information about the displacement field, which is directly related to strain. Lattice strain in the catalysts impacts their electronic configuration and, consequently, their binding energy with reaction intermediates. Even though there have been significant improvements since its birth, the fact that the experiments can only be performed at synchrotron facilities and its relatively low resolution to date (∼10 nm spatial resolution) have prevented the popularization of this technique. Herein, we will briefly describe the fundamentals of the technique, including the electrocatalysis relevant information that we can extract from it. Subsequently, we review some of the computational experiments that complement the BCDI data for enhanced information extraction and improved understanding of the underlying nanoscale electrocatalytic processes. We next highlight success stories of BCDI applied to different electrochemical systems and in heterogeneous catalysis to show how the technique can contribute to future studies in electrocatalysis. Finally, we outline current challenges in spatiotemporal resolution limits of BCDI and provide our perspectives on recent developments in synchrotron facilities as well as the role of machine learning and artificial intelligence in addressing them.

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Section: Fundamental Aspects Of Bcdimentioning

confidence: 99%

Bragg Coherent Diffraction Imaging for In Situ Studies in Electrocatalysis

et al. 2021

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“…It would be desirable to repeat similar measurements at other photon energies throughout the whole energy range of this instrument (4 to 20 keV), but is beyond the scope of the present manuscript. The estimated transverse normalized degree of coherence F could also be measured more directly by an experiment based on a Young's double slit (Lyubomirskiy et al, 2016) or on a non-redundant array of slits (Westfahl et al, 2017). The advantage of the ptychographic method presented here is that the retrieved set of coherent modes can be treated the same way as the simulated modes, which allows for a direct comparison.…”

Section: Coherence Properties Of the Beammentioning

confidence: 96%

Measurement of the coherent beam properties at the CoSAXS beamline

Kahnt¹,

Klementiev²,

Haghighat³

et al. 2021

J Synchrotron Radiat

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The CoSAXS beamline at the MAX IV Laboratory is a modern multi-purpose (coherent) small-angle X-ray scattering (CoSAXS) instrument, designed to provide intense and optionally coherent illumination at the sample position, enabling coherent imaging and speckle contrast techniques. X-ray tracing simulations used to design the beamline optics have predicted a total photon flux of 1012–1013 photons s−1 and a degree of coherence of up to 10% at 7.1 keV. The normalized degree of coherence and the coherent flux of this instrument were experimentally determined using the separability of a ptychographic reconstruction into multiple mutually incoherent modes and thus the Coherence in the name CoSAXS was verified. How the beamline can be used both for coherent imaging and XPCS measurements, which both heavily rely on the degree of coherence of the beam, was demonstrated. These results are the first experimental quantification of coherence properties in a SAXS instrument at a fourth-generation synchrotron light source.

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“…A quadrupole doublet is used to match the arcs to the high beta sections whereas a quadrupole triplet is used for the low beta ones. In the low beta sections, we have simultaneously focused both the x and y beta functions to 1.5 m at the centre of the straight section to improve the phase-space matching of the electron beam to the photon beam from undulators [5]. The optics is fivefold symmetric with 15 low and 5 high beta sections.…”

Section: Sirius Lattice Design and Opticsmentioning

confidence: 99%

Synchrotron radiation sources in Brazil

Liu

Neuenschwander

Rodrigues

2019

Phil. Trans. R. Soc. A.

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The development of synchrotron radiation sources in Brazil is described from a brief historical point of view followed by a description of the Sirius project, a new 3 GeV fourth-generation synchrotron light source with 518 m circumference and 0.25 nm.rad emittance, in final construction stage at the Brazilian Synchrotron Light Laboratory campus, in Campinas. As one of the pioneer fourth-generation machines, many accelerator engineering challenges were studied in depth and resulted in quite a few innovative developments. In this paper, we review some of these developments. This article is part of the theme issue ‘Fifty years of synchrotron science: achievements and opportunities’.

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The coherent radiation fraction of low-emittance synchrotrons

Cited by 12 publications

References 24 publications

Bragg Coherent Diffraction Imaging for In Situ Studies in Electrocatalysis

Bragg Coherent Diffraction Imaging for In Situ Studies in Electrocatalysis

Measurement of the coherent beam properties at the CoSAXS beamline

Synchrotron radiation sources in Brazil

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