The Potential of EuPRAXIA@SPARC_LAB for Radiation Based Techniques

A proposal for building a Free Electron Laser, EuPRAXIA@SPARC_LAB, at the Laboratori Nazionali di Frascati, is at present under consideration. This FEL facility will provide a unique combination of a high brightness GeV-range electron beam generated in a X-band RF linac, a 0.5 PW-class laser system and the first FEL source driven by a plasma accelerator. The FEL will produce ultra-bright pulses, with up to 10 12 photons/pulse, femtosecond timescale and wavelength down to 3 nm, which lies in the so called “water window”. The experimental activity will be focused on the realization of a plasma driven short wavelength FEL able to provide high-quality photons for a user beamline. In this paper, we describe the main classes of experiments that will be performed at the facility, including coherent diffraction imaging, soft X-ray absorption spectroscopy, Raman spectroscopy, Resonant Inelastic X-ray Scattering and photofragmentation measurements. These techniques will allow studying a variety of samples, both biological and inorganic, providing information about their structure and dynamical behavior. In this context, the possibility of inducing changes in samples via pump pulses leading to the stimulation of chemical reactions or the generation of coherent excitations would tremendously benefit from pulses in the soft X-ray region. High power synchronized optical lasers and a TeraHertz radiation source will indeed be made available for THz and pump–probe experiments and a split-and-delay station will allow performing XUV-XUV pump–probe experiments.

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A high-pressure cryocooling method for protein crystals and biological samples with reduced background X-ray scatter

Journal of Applied Crystallography ◽

10.1107/s0021889812045013 ◽

2012 ◽

Vol 46 (1) ◽

pp. 234-241 ◽

Cited By ~ 11

Author(s):

Chae Un Kim ◽

Jennifer L. Wierman ◽

Richard Gillilan ◽

Enju Lima ◽

Sol M. Gruner

Keyword(s):

High Pressure ◽

Biological Samples ◽

Protein Crystal ◽

High Background ◽

X Ray ◽

Coherent Diffraction Imaging ◽

X Ray Scattering ◽

Alternative Method ◽

Helium Gas ◽

Diffraction Imaging

High-pressure cryocooling has been developed as an alternative method for cryopreservation of macromolecular crystals and successfully applied for various technical and scientific studies. The method requires the preservation of crystal hydration as the crystal is pressurized with dry helium gas. Previously, crystal hydration was maintained either by coating crystals with a mineral oil or by enclosing crystals in a capillary which was filled with crystallization mother liquor. These methods are not well suited to weakly diffracting crystals because of the relatively high background scattering from the hydrating materials. Here, an alternative method of crystal hydration, called capillary shielding, is described. The specimen is kept hydratedviavapor diffusion in a shielding capillary while it is being pressure cryocooled. After cryocooling, the shielding capillary is removed to reduce background X-ray scattering. It is shown that, compared to previous crystal-hydration methods, the new hydration method produces superior crystal diffraction with little sign of crystal damage. Using the new method, a weakly diffracting protein crystal may be properly pressure cryocooled with little or no addition of external cryoprotectants, and significantly reduced background scattering can be observed from the resulting sample. Beyond the applications for macromolecular crystallography, it is shown that the method has great potential for the preparation of noncrystalline hydrated biological samples for coherent diffraction imaging with future X-ray sources.

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Single-Shot Coherent X-Ray Imaging Instrument at PAL-XFEL

Applied Sciences ◽

10.3390/app11115082 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5082

Author(s):

Daeho Sung ◽

Daewoong Nam ◽

Myong-jin Kim ◽

Seonghan Kim ◽

Kyung Sook Kim ◽

...

Keyword(s):

Correlation Spectroscopy ◽

Single Shot ◽

Pump Probe ◽

X Ray ◽

Coherent Diffraction Imaging ◽

X Ray Imaging ◽

Scattering Geometry ◽

Diffraction Imaging ◽

Imaging Instrument ◽

Pal Xfel

We developed a single-shot coherent X-ray imaging instrument at the hard X-ray beamline of the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL). This experimental platform was established to conduct a variety of XFEL experiments, including coherent diffraction imaging (CDI), X-ray photon correlation spectroscopy (XPCS), and coherent X-ray scattering (CXS). Based on the forward-scattering geometry, this instrument utilizes a fixed-target method for sample delivery. It is well optimized for single-shot-based experiments in which one expects to observe the ultrafast phenomena of nanoparticles at picosecond temporal and nanometer spatial resolutions. In this paper, we introduce a single-shot coherent X-ray imaging instrument and report pump–probe coherent diffraction imaging (PPCDI) of Ag nanoparticles as an example of its applications.

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Coherent X-ray scattering beamline at port 9C of Pohang Light Source II

Journal of Synchrotron Radiation ◽

10.1107/s1600577513025629 ◽

2013 ◽

Vol 21 (1) ◽

pp. 264-267 ◽

Cited By ~ 5

Author(s):

Chung-Jong Yu ◽

Hae Cheol Lee ◽

Chan Kim ◽

Wonsuk Cha ◽

Jerome Carnis ◽

...

Keyword(s):

Light Source ◽

Correlation Spectroscopy ◽

X Rays ◽

Photon Correlation ◽

X Ray ◽

Coherent Diffraction Imaging ◽

X Ray Scattering ◽

Pohang Light Source ◽

Diffraction Imaging ◽

Ray Scattering

The coherent X-ray scattering beamline at the 9C port of the upgraded Pohang Light Source (PLS-II) at Pohang Accelerator Laboratory in Korea is introduced. This beamline provides X-rays of 5–20 keV, and targets coherent X-ray experiments such as coherent diffraction imaging and X-ray photon correlation spectroscopy. The main parameters of the beamline are summarized, and some preliminary experimental results are described.

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Skopi: a simulation package for diffractive imaging of noncrystalline biomolecules

10.1101/2021.12.09.471972 ◽

2021 ◽

Author(s):

Ariana Peck ◽

Hsing-Yin Chang ◽

Antoine Dujardin ◽

Deeban Ramalingam ◽

Monarin Uervirojnangkoorn ◽

...

Keyword(s):

Reconstruction Algorithms ◽

Diffractive Imaging ◽

X Ray ◽

Machine Learning Classification ◽

Coherent Diffraction Imaging ◽

X Ray Scattering ◽

Diffraction Imaging ◽

Classification Tasks ◽

And Function ◽

Simulation Package

X-ray free electron lasers (XFEL) have the ability to produce ultra-bright femtosecond X-ray pulses for coherent diffraction imaging of biomolecules. While the development of methods and algorithms for macromolecular crystallography is now mature, XFEL experiments involving aerosolized or solvated biomolecular samples offer new challenges both in terms of experimental design and data processing. Skopi is a simulation package that can generate single-hit diffraction images for reconstruction algorithms, multi-hit diffraction images of aggregated particles for training machine learning classification tasks using labeled data, diffraction images of randomly distributed particles for fluctuation X-ray scattering (FXS) algorithms, and diffraction images of reference and target particles for holographic reconstruction algorithms. We envision skopi as a resource to aid the development of on-the-fly feedback during non-crystalline experiments at XFEL facilities, which will provide critical insights into biomolecular structure and function.

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Advanced calculations of X-ray spectroscopies with FEFF10 and Corvus

Journal of Synchrotron Radiation ◽

10.1107/s1600577521008614 ◽

2021 ◽

Vol 28 (6) ◽

Author(s):

J. J. Kas ◽

F. D. Vila ◽

C. D. Pemmaraju ◽

T. S. Tan ◽

J. J. Rehr

Keyword(s):

Real Space ◽

Vibrational Properties ◽

Many Body ◽

Edge Structure ◽

Pump Probe ◽

X Ray ◽

X Ray Scattering ◽

Function Code ◽

Electron Energy Loss ◽

X Ray Absorption

The real-space Green's function code FEFF has been extensively developed and used for calculations of X-ray and related spectra, including X-ray absorption (XAS), X-ray emission (XES), inelastic X-ray scattering, and electron energy-loss spectra. The code is particularly useful for the analysis and interpretation of the XAS fine-structure (EXAFS) and the near-edge structure (XANES) in materials throughout the periodic table. Nevertheless, many applications, such as non-equilibrium systems, and the analysis of ultra-fast pump–probe experiments, require extensions of the code including finite-temperature and auxiliary calculations of structure and vibrational properties. To enable these extensions, we have developed in tandem a new version FEFF10 and new FEFF-based workflows for the Corvus workflow manager, which allow users to easily augment the capabilities of FEFF10 via auxiliary codes. This coupling facilitates simplified input and automated calculations of spectra based on advanced theoretical techniques. The approach is illustrated with examples of high-temperature behavior, vibrational properties, many-body excitations in XAS, super-heavy materials, and fits of calculated spectra to experiment.

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Vibrational resonant inelastic X-ray scattering in liquid acetic acid: a ruler for molecular chain lengths

Scientific Reports ◽

10.1038/s41598-021-83248-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Viktoriia Savchenko ◽

Iulia Emilia Brumboiu ◽

Victor Kimberg ◽

Michael Odelius ◽

Pavel Krasnov ◽

...

Keyword(s):

Molecular Structure ◽

Acetic Acid ◽

Molecular Chain ◽

X Ray ◽

X Ray Scattering ◽

Localized Excitations ◽

Vibrational Excitations ◽

Chain Lengths ◽

X Ray Absorption ◽

Ray Scattering

AbstractQuenching of vibrational excitations in resonant inelastic X-ray scattering (RIXS) spectra of liquid acetic acid is observed. At the oxygen core resonance associated with localized excitations at the O–H bond, the spectra lack the typical progression of vibrational excitations observed in RIXS spectra of comparable systems. We interpret this phenomenon as due to strong rehybridization of the unoccupied molecular orbitals as a result of hydrogen bonding, which however cannot be observed in x-ray absorption but only by means of RIXS. This allows us to address the molecular structure of the liquid, and to determine a lower limit for the average molecular chain length.

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Crystalline and magnetic structure of Ba2CuO3+δ investigated by x-ray absorption spectroscopy and resonant inelastic x-ray scattering

Physica C Superconductivity ◽

10.1016/j.physc.2020.1353810 ◽

2020 ◽

pp. 1353810

Author(s):

Roberto Fumagalli ◽

Abhishek Nag ◽

Stefano Agrestini ◽

Mirian Garcia-Fernandez ◽

Andrew C. Walters ◽

...

Keyword(s):

Magnetic Structure ◽

Absorption Spectroscopy ◽

X Ray ◽

X Ray Scattering ◽

X Ray Absorption ◽

Ray Scattering

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Structure of the manganese complex in photosystem II: insights from X–ray spectroscopy

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2002.1133 ◽

2002 ◽

Vol 357 (1426) ◽

pp. 1347-1358 ◽

Cited By ~ 48

Author(s):

Vittal K. Yachandra

Keyword(s):

Fine Structure ◽

Emission Spectroscopy ◽

Structural Models ◽

Oxidation States ◽

X Ray ◽

X Ray Scattering ◽

Raman Process ◽

Mn Cluster ◽

X Ray Absorption ◽

S States

We have used Mn K–edge absorption and Kβ emission spectroscopy to determine the oxidation states of the Mn complex in the various S states. We have started exploring the new technique of resonant inelastic X–ray scattering spectroscopy; this technique can be characterized as a Raman process that uses K–edge energies (1s to 4p, ca . 6550 eV) to obtain L–edge–like spectra (2p to 3d, ca . 650 eV). The relevance of these data to the oxidation states and structure of the Mn complex is presented. We have obtained extended X–ray absorption fine structure data from the S 0 and S 3 states and observed heterogeneity in the Mn–Mn distances leading us to conclude that there may be three rather than two di– μ –oxo–bridged units present per tetranuclear Mn cluster. In addition, we have obtained data using Ca and Sr X–ray spectroscopy that provide evidence for a heteronuclear Mn1Ca cluster. The possibility of three di– μ –oxo–bridged Mn–Mn moieties and the proximity of Ca is incorporated into developing structural models for the Mn cluster. The involvement of bridging and terminal O ligands of Mn in the mechanism of oxygen evolution is discussed in the context of our X–ray spectroscopy results.

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In Situ Investigation of the Early-Stage Growth of Nanoporous Alumina

Journal of Nanomaterials ◽

10.1155/2018/6428271 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9

Author(s):

Thérèse Gorisse ◽

Ludovic Dupré ◽

Marc Zelsmann ◽

Alina Vlad ◽

Alessandro Coati ◽

...

Keyword(s):

Early Stage ◽

Grazing Incidence ◽

Alumina Layer ◽

Nanoporous Alumina ◽

X Ray ◽

X Ray Scattering ◽

In Situ Investigation ◽

Low X ◽

X Ray Absorption

We report the successful use of in situ grazing incidence small-angle X-ray scattering to follow the anodization of aluminum. A dedicated electrochemical cell was designed and developed for this purpose with low X-ray absorption, with the possibility to access all azimuthal angles (360°) and to remotely control the temperature of the electrolyte. Three well-known fabrication techniques of nanoporous alumina, i.e., single, double, and pretextured, were investigated. The differences in the evolution of the scattering images are described and explained. From these measurements, we could determine at which moment the pores start growing even for very short anodization times. Furthermore, we could follow the thickness of the alumina layer as a function of the anodization time by monitoring the period of the Kiessig fringes. This work is aimed at helping to understand the different steps taking place during the anodization of aluminum at the very early stages of nanoporous alumina formation.

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