High-Throughput Asymmetric Double-Crystal Monochromator of the SAXS Beamline at ELETTRA

A new high-flux wiggler beamline for fast time-resolved small-angle X-ray scattering (SAXS) based on double-focusing optics has recently commenced operation at the 2 GeV third-generation storage ring ELETTRA at Trieste, Italy. Its non-dispersive double-crystal monochromator contains three pairs of interchangeable asymmetrically cut flat Si(111)-crystal pairs, each of which is optimized for high throughput at one of the three fixed energies 5.4, 8 and 16 keV. To cope with the severe thermal power load produced by a 57-pole wiggler on the first crystal of each pair (up to 5.4 W mm−2 and 700 W under normal incidence, for 400 mA), grazing angles of 2° and optimized back-cooling have been chosen. This solution allows simultaneously a gain of 2.5–3.0 in throughput and, accordingly, in flux density. Finite-element analysis as well as commissioning tests showed that the cooling layout functions very satisfactorily, and that up to 5 × 1012 photons s−1 are available at the sample (at 8 keV and 250 mA), as predicted.

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Time-resolved XAFS measurement using quick-scanning techniques at BSRF

Journal of Synchrotron Radiation ◽

10.1107/s1600577517005276 ◽

2017 ◽

Vol 24 (3) ◽

pp. 674-678 ◽

Cited By ~ 3

Author(s):

Shengqi Chu ◽

Lirong Zheng ◽

Pengfei An ◽

Hui Gong ◽

Tiandou Hu ◽

...

Keyword(s):

Signal To Noise Ratio ◽

High Energy ◽

High Energy Resolution ◽

Double Crystal ◽

Time Resolved ◽

Edge Structure ◽

X Ray ◽

Double Crystal Monochromator ◽

Good Signal ◽

X Ray Absorption

A new quick-scanning X-ray absorption fine-structure (QXAFS) system has been established on beamline 1W1B at the Beijing Synchrotron Radiation Facility. As an independent device, the QXAFS system can be employed by other beamlines equipped with a double-crystal monochromator to carry out quick energy scans and data acquisition. Both continuous-scan and trapezoidal-scan modes are available in this system to satisfy the time scale from subsecond (in the X-ray absorption near-edge structure region) to 1 min. Here, the trapezoidal-scan method is presented as being complementary to the continuous-scan method, in order to maintain high energy resolution and good signal-to-noise ratio. The system is demonstrated to be very reliable and has been combined with in situ cells to carry out time-resolved XAFS studies.

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Augmentation of the step-by-step Energy-Scanning EXAFS beamline BL-09 to continuous-scan EXAFS mode at INDUS-2 SRS

Journal of Synchrotron Radiation ◽

10.1107/s160057751601362x ◽

2016 ◽

Vol 23 (6) ◽

pp. 1518-1525 ◽

Cited By ~ 5

Author(s):

Ashwini Kumar Poswal ◽

Ankur Agrawal ◽

Himanshu Kumar Poswal ◽

Dibyendu Bhattacharyya ◽

Shambhu Nath Jha ◽

...

Keyword(s):

Signal To Noise Ratio ◽

Energy Calibration ◽

Acquisition Time ◽

High Signal ◽

Signal To Noise ◽

Double Crystal ◽

Time Resolved ◽

Synchrotron Source ◽

Double Crystal Monochromator

An innovative scheme to carry out continuous-scan X-ray absorption spectroscopy (XAS) measurements similar to quick-EXAFS mode at the Energy-Scanning EXAFS beamline BL-09 at INDUS-2 synchrotron source (Indore, India), which is generally operated in step-by-step scanning mode, is presented. The continuous XAS mode has been implemented by adopting a continuous-scan scheme of the double-crystal monochromator and on-the-fly measurement of incident and transmitted intensities. This enabled a high signal-to-noise ratio to be maintained and the acquisition time was reduced to a few seconds from tens of minutes or hours. The quality of the spectra (signal-to-noise level, resolution and energy calibration) was checked by measuring and analysing XAS spectra of standard metal foils. To demonstrate the energy range covered in a single scan, a continuous-mode XAS spectrum of copper nickel alloy covering both Cu and NiK-edges was recorded. The implementation of continuous-scan XAS mode at BL-09 would expand the use of this beamline inin situtime-resolved XAS studies of various important systems of current technological importance. The feasibility of employing this mode of measurement for time-resolved probing of reaction kinetics has been demonstrated byin situXAS measurement on the growth of Ag nanoparticles from a solution phase.

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A Wide-Bandpass Multilayer Monochromator for Biological Small-Angle Scattering and Fiber Diffraction Studies

Journal of Applied Crystallography ◽

10.1107/s0021889898002702 ◽

1998 ◽

Vol 31 (5) ◽

pp. 672-682 ◽

Cited By ~ 28

Author(s):

Hiro Tsuruta ◽

Sean Brennan ◽

Zofia U. Rek ◽

Thomas C. Irving ◽

W. H. Tompkins ◽

...

Keyword(s):

Small Angle ◽

Double Crystal ◽

Time Resolved ◽

X Ray ◽

Double Crystal Monochromator ◽

X Ray Scattering ◽

Fiber Diffraction ◽

Angle Scattering ◽

Flux Level ◽

Ray Scattering

Many biological applications of small-angle X-ray scattering, in particular time-resolved studies, are often limited by the flux incident on the sample due to the smaller scattering cross section of biological specimens. The wider-energy bandpass of a monochromator that consists of a pair of synthetic multilayer microstructures can, in principle, provide a flux two orders of magnitude higher than that of an Si(111) double-crystal monochromator. Two types of multilayers have been installed in the standard monochromator tank of beamline 4-2 at the Stanford Synchrotron Radiation Laboratory; the multilayer beam has been characterized for studies of small-angle X-ray scattering/diffraction from biological materials. Reflectivity and topography measurements indicate that the multilayers are quite adequate for these applications and a pair of Mo/B4C multilayers provided a 10–30 times increase in flux, compared with the flux level obtained with an Si(111) double-crystal monochromator. The increased flux level is very useful in time-resolved scattering studies as well as for recording weak scattering at higher angles. Having carried out many solution scattering and fiber diffraction experiments, we conclude that the use of multilayer does not result in significant broadening of diffraction peaks nor does it have appreciable effects on small-angle resolution. No significant increase in background is observed.

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Characterization of a bent Laue double-crystal beam-expanding monochromator

Journal of Synchrotron Radiation ◽

10.1107/s1600577517014059 ◽

2017 ◽

Vol 24 (6) ◽

pp. 1146-1151 ◽

Cited By ~ 3

Author(s):

Mercedes Martinson ◽

Nazanin Samadi ◽

Xianbo Shi ◽

Zunping Liu ◽

Lahsen Assoufid ◽

...

Keyword(s):

Imaging Techniques ◽

Silicon Crystal ◽

Large Field ◽

Element Analysis ◽

Double Crystal ◽

Double Crystal Monochromator ◽

Global Mapping ◽

Diffraction Effects ◽

Crystal Wafer ◽

Bent Crystals

A bent Laue double-crystal monochromator system has been designed for vertically expanding the X-ray beam at the Canadian Light Source's BioMedical Imaging and Therapy beamlines. Expansion by a factor of 12 has been achieved without deteriorating the transverse coherence of the beam, allowing phase-based imaging techniques to be performed with high flux and a large field of view. However, preliminary studies revealed a lack of uniformity in the beam, presumed to be caused by imperfect bending of the silicon crystal wafers used in the system. Results from finite-element analysis of the system predicted that the second crystal would be most severely affected and has been shown experimentally. It has been determined that the majority of the distortion occurs in the second crystal and is likely caused by an imperfection in the surface of the bending frame. Measurements were then taken to characterize the bending of the crystal using both mechanical and diffraction techniques. In particular, two techniques commonly used to map dislocations in crystal structures have been adapted to map local curvature of the bent crystals. One of these, a variation of Berg–Berrett topography, has been used to quantify the diffraction effects caused by the distortion of the crystal wafer. This technique produces a global mapping of the deviation of the diffraction angle relative to a perfect cylinder. This information is critical for improving bending and measuring tolerances of imperfections by correlating this mapping to areas of missing intensity in the beam.

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In Situ Gas Supply System on the Powder Diffraction Beamline I11 at Diamond Light Source

Materials Science Forum ◽

10.4028/www.scientific.net/msf.706-709.1707 ◽

2012 ◽

Vol 706-709 ◽

pp. 1707-1712 ◽

Cited By ~ 17

Author(s):

J.E. Parker ◽

J. Potter ◽

S.P. Thompson ◽

A.R. Lennie ◽

C.C. Tang

Keyword(s):

Powder Diffraction ◽

High Pressures ◽

High Angular Resolution ◽

X Rays ◽

Double Crystal ◽

Time Resolved ◽

Double Crystal Monochromator ◽

Harmonic Rejection ◽

Capillary Sample

Beamline I11 at Diamond began accepting users for high resolution powder diffraction experiments in Oct 2008. We present the design, key specifications, performance and the hardware of this new beamline which receives an intense and highly collimated x-ray beam generated by an in-vacuum undulator. With the simple optics (a double-crystal monochromator, harmonic rejection mirrors and slits), a high purity beam of low energy-bandpass X-rays optimised at 15 keV is delivered at the sample. The heavy duty diffraction instrument is designed to have the flexibility to house a variety of sample environments and holds two detection systems to collect high quality diffraction data, i.e. multi-analysing crystals (MAC) for high angular resolution experiments and a fast position sensitive detector (PSD) for time-resolved studies. A recent addition to the beamline capabilities is the installation of a specifically designed gas control system. This allows the in-situ dosing of a powder sample with gases such as hydrogen and carbon dioxide, at low (~10 mbar) and high pressures (<100 bar). In addition a low pressure capillary sample cell is described which is now available to users of the beamline.

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High-power-load DCLM monochromator for a computed tomography program at BMIT at energies of 25–150 keV

Journal of Synchrotron Radiation ◽

10.1107/s1600577518008639 ◽

2018 ◽

Vol 25 (5) ◽

pp. 1548-1555

Author(s):

Tomasz W. Wysokinski ◽

Michel Renier ◽

Pekka Suortti ◽

George Belev ◽

Léo Rousset ◽

...

Keyword(s):

Mechanical Properties ◽

Biomedical Imaging ◽

Large Scale ◽

Fine Tuning ◽

Wide Energy Range ◽

Contrast Imaging ◽

Element Analysis ◽

Double Crystal ◽

Crystal Water ◽

Power Load

The research program at the biomedical imaging facility requires a high-flux hard-X-ray monochromator that can also provide a wide beam. A wide energy range is needed for standard radiography, phase-contrast imaging, K-edge subtraction imaging and monochromatic beam therapy modalities. The double-crystal Laue monochromator, developed for the BioMedical Imaging and Therapy facility, is optimized for the imaging of medium- and large-scale samples at high energies with the resolution reaching 4 µm. A pair of 2 mm-thick Si(111) bent Laue-type crystals were used in fixed-exit beam mode with a 16 mm vertical beam offset and the first crystal water-cooled. The monochromator operates at energies from 25 to 150 keV, and the measured size of the beam is 189 mm (H) × 8.6 mm (V) at 55 m from the source. This paper presents our approach in developing a complete focusing model of the monochromator. The model uses mechanical properties of crystals and benders to obtain a finite-element analysis of the complete assembly. The modeling results are compared and calibrated with experimental measurements. Using the developed analysis, a rough estimate of the bending radius and virtual focus (image) position of the first crystal can be made, which is also the real source for the second crystal. On the other hand, by measuring the beam height in several points in the SOE-1 hutch, the virtual focus of the second crystal can be estimated. The focusing model was then calibrated with measured mechanical properties, the values for the force and torque applied to the crystals were corrected, and the actual operating parameters of the monochromator for fine-tuning were provided.

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Trace element analysis on Si wafer surfaces by TXRF at the ID32 ESRF undulator beamline

Journal of Synchrotron Radiation ◽

10.1107/s0909049597016737 ◽

1998 ◽

Vol 5 (3) ◽

pp. 1064-1066 ◽

Cited By ~ 15

Author(s):

Luc Ortega ◽

Fabio Comin ◽

Vincenzo Formoso ◽

Andreas Stierle

Keyword(s):

Synchrotron Radiation ◽

Trace Element ◽

Trace Element Analysis ◽

Element Analysis ◽

Double Crystal ◽

X Ray ◽

Double Crystal Monochromator ◽

First Results ◽

Set Up ◽

Wave Methods

Synchrotron radiation total-reflection X-ray fluorescence (SR-TXRF) has been applied to the impurity analysis of Si wafers using a third-generation synchrotron radiation undulator source. A lower limit of detectability (LLD) for Ni atoms of 17 fg (1.7 × 108 atoms cm−2) has been achieved with an optical set-up based on an Si(111) double-crystal monochromator and a horizontal sample geometry. These first results are very promising for synchrotron radiation trace element analysis since we estimate that it is possible to lower the LLD by a factor of about 25 by employing appropriate optics and detectors. The use of a crystal monochromator opens new possibilities to perform absorption and scattering experiments (NEXAFS and X-ray standing-wave methods) for chemical and structural analysis of ultratrace elements.

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