scholarly journals The potential of future light sources to explore the structure and function of matter

IUCrJ ◽  
2015 ◽  
Vol 2 (2) ◽  
pp. 230-245 ◽  
Author(s):  
Edgar Weckert
Keyword(s):  
Storage Ring ◽  
Structural Changes ◽  
Imaging Techniques ◽  
Single Pulse ◽  
Storage Rings ◽  
Correlation Spectroscopy ◽  
Light Sources ◽  
Spectral Brightness ◽  
Diffractive Imaging ◽  
X Ray

Structural studies in general, and crystallography in particular, have benefited and still do benefit dramatically from the use of synchrotron radiation. Low-emittance storage rings of the third generation provide focused beams down to the micrometre range that are sufficiently intense for the investigation of weakly scattering crystals down to the size of several micrometres. Even though the coherent fraction of these sources is below 1%, a number of new imaging techniques have been developed to exploit the partially coherent radiation. However, many techniques in nanoscience are limited by this rather small coherent fraction. On the one hand, this restriction limits the ability to study the structure and dynamics of non-crystalline materials by methods that depend on the coherence properties of the beam, like coherent diffractive imaging and X-ray correlation spectroscopy. On the other hand, the flux in an ultra-small diffraction-limited focus is limited as well for the same reason. Meanwhile, new storage rings with more advanced lattice designs are under construction or under consideration, which will have significantly smaller emittances. These sources are targeted towards the diffraction limit in the X-ray regime and will provide roughly one to two orders of magnitude higher spectral brightness and coherence. They will be especially suited to experiments exploiting the coherence properties of the beams and to ultra-small focal spot sizes in the regime of several nanometres. Although the length of individual X-ray pulses at a storage-ring source is of the order of 100 ps, which is sufficiently short to track structural changes of larger groups, faster processes as they occur during vision or photosynthesis, for example, are not accessible in all details under these conditions. Linear accelerator (linac) driven free-electron laser (FEL) sources with extremely short and intense pulses of very high coherence circumvent some of the limitations of present-day storage-ring sources. It has been demonstrated that their individual pulses are short enough to outrun radiation damage for single-pulse exposures. These ultra-short pulses also enable time-resolved studies 1000 times faster than at standard storage-ring sources. Developments are ongoing at various places for a totally new type of X-ray source combining a linac with a storage ring. These energy-recovery linacs promise to provide pulses almost as short as a FEL, with brilliances and multi-user capabilities comparable with a diffraction-limited storage ring. Altogether, these new X-ray source developments will provide smaller and more intense X-ray beams with a considerably higher coherent fraction, enabling a broad spectrum of new techniques for studying the structure of crystalline and non-crystalline states of matter at atomic length scales. In addition, the short X-ray pulses of FELs will enable the study of fast atomic dynamics and non-equilibrium states of matter.

scholarly journals The potential of future light sources to explore the structure and function of matter

2014 ◽  
Vol 70 (a1) ◽  
pp. C31-C31
Author(s):  
Edgar Weckert
Keyword(s):  
Storage Ring ◽  
Structural Changes ◽  
Single Pulse ◽  
Storage Rings ◽  
Correlation Spectroscopy ◽  
Light Sources ◽  
Structural Studies ◽  
Diffractive Imaging ◽  
X Ray ◽  
Stage Of Development

Structural studies in general and in particular in crystallography have benefited and still do benefit dramatically from the use of synchrotron radiation. Its tuneability is mandatory for multi or single anomalous diffraction experiments, still one of the main methods for solving new crystal structures. Its tuneability is also a key for spectroscopy techniques for the determination of the local atomic environment around and the oxidation state of an absorbing atom. These techniques are powerful tools e.g. in chemistry to study reactions, and can be applied not only to crystalline matter. Low emittance storage rings of the third generation with their highly brilliant X-ray beams enable us to focus beams down to the micrometer range intense enough for the investigation of weakly scattering crystals down to the size of several micrometers. Considering these highly intense beams, if it comes to structural studies using X-ray, what are still the limitations of the most modern storage ring sources? The length of individual X-ray pulses is in the order of 100 ps, which is sufficient to trace structural changes of larger groups or the diffusion of atoms over larger atomic distances. However, fast processes as they occur e.g. during vision or photosynthesis are not accessible by these means. Also the coherent fraction of the radiation of present day storage rings in the X-ray regime is rather low (i.g. < 1 %). This limits on one hand our ability to study the structure and dynamic of non-crystalline materials by methods exploiting the coherence properties of the beam like coherent diffractive imaging and X-ray correlation spectroscopy, respectively. On the other hand the flux in an ultra small diffraction-limited focus is limited as well. Upcoming linac driven free electron laser (FEL) sources with extremely short (sub 100 fs) and intense pulse (~10^12 ph) of very high coherence circumvent some of the limitations of present day storage rings. It has been demonstrated that their individual pulses are short enough to outrun radiation damage for single pulse exposures. First structures from sub micrometer crystals using an X-ray FEL (LCLS, Stanford) have already been published. These ultra short pulses also enable time resolved studies 1000 times faster than at standard storage ring sources. Meanwhile new storage rings with more aggressive lattice designs are under construction or under consideration with significantly smaller emittances. These sources target towards the diffraction limit in the X-ray regime and will provide roughly one to two orders of magnitude higher brilliance and coherence. They will be especially suited to those experiments exploiting the coherence properties of the beams and to ultra small focal spot sizes in the several nm regime. Developments at various places are ongoing for a totally new type of X-ray source combining a linac with a storage ring. This so called energy recovery linacs (ERL) promise to provide pulses almost as short as at an FEL with brilliances and multi-user capabilities comparable to a diffraction limited storage ring. The contribution will try to give an overview of the stage of development of the various source projects and their possible impact on structural studies in future.

Generation of picosecond electron bunches in storage rings

2014 ◽  
Vol 21 (5) ◽  
pp. 961-967 ◽  
Author(s):  
Xiaobiao Huang ◽  
Thomas Rabedeau ◽  
James Safranek
Keyword(s):  
Storage Ring ◽  
Short Pulse ◽  
Storage Rings ◽  
High Repetition Rate ◽  
Light Sources ◽  
X Ray ◽  
Electron Bunches ◽  
Performance Challenges ◽  
Synchrotron Light Sources ◽  
Srf Cavities

Approaches to generating short X-ray pulses in synchrotron light sources are discussed. In particular, the method of using a superconducting harmonic cavity to generate simultaneously long and short bunches in storage rings and the approach of injecting short bunches from a linac injector into a storage ring for multi-turn circulation are emphasized. If multi-cell superconducting RF (SRF) cavities with frequencies of ∼1.5 GHz can be employed in storage rings, it would be possible to generate stable, high-flux, short-pulse X-ray beams with pulse lengths of 1–10 ps (FWHM) in present or future storage rings. However, substantial challenges exist in adapting today's high-gradient SRF cavities for high-current storage ring operation. Another approach to generating short X-ray pulses in a storage ring is injecting short-pulse electron bunches from a high-repetition-rate linac injector for circulation. Its performance is limited by the microbunching instability due to coherent synchrotron radiation. Tracking studies are carried out to evaluate its performance. Challenges and operational considerations for this mode are considered.

scholarly journals Nanosecond X-ray photon correlation spectroscopy using pulse time structure of a storage-ring source

IUCrJ ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 124-130
Author(s):  
Wonhyuk Jo ◽  
Fabian Westermeier ◽  
Rustam Rysov ◽  
Olaf Leupold ◽  
Florian Schulz ◽  
...  
Keyword(s):  
Storage Ring ◽  
Photon Correlation Spectroscopy ◽  
Single Pulse ◽  
Correlation Spectroscopy ◽  
Photon Flux ◽  
Pixel Detector ◽  
Photon Correlation ◽  
X Ray ◽  
Speckle Patterns ◽  
Nanosecond Time Resolution

X-ray photon correlation spectroscopy (XPCS) is a routine technique to study slow dynamics in complex systems at storage-ring sources. Achieving nanosecond time resolution with the conventional XPCS technique is, however, still an experimentally challenging task requiring fast detectors and sufficient photon flux. Here, the result of a nanosecond XPCS study of fast colloidal dynamics is shown by employing an adaptive gain integrating pixel detector (AGIPD) operated at frame rates of the intrinsic pulse structure of the storage ring. Correlation functions from single-pulse speckle patterns with the shortest correlation time of 192 ns have been calculated. These studies provide an important step towards routine fast XPCS studies at storage rings.

Photon Science at Accelerator-Based Light Sources

2010 ◽  
Vol 03 (01) ◽  
pp. 13-37 ◽  
Author(s):  
Jochen R. Schneider
Keyword(s):  
Storage Ring ◽  
Free Electron ◽  
Light Sources ◽  
Spectral Brightness ◽  
Third Generation ◽  
Free Electron Lasers ◽  
X Ray ◽  
Single Pass ◽  
The 1960S ◽  
Photon Science

Accelerator-based light sources stimulated progress in photon science in a truly extraordinary manner. The spectral brightness of storage-ring-based facilities increased by three orders of magnitude every 10 years since the 1960s. The extreme peak brightness at single-pass free electron X-ray lasers with pulse durations variable between about 1 and 300 femtoseconds will allow transformative experiments in many areas of science. This article is an attempt to show how progress in accelerator science and technology stimulated advancement in photon science, by discussing a limited number of examples of work at third generation storage ring facilities and free electron lasers. Hopes for further improvements in specific beam properties are expressed.

Accelerator-based X-ray sources: synchrotron radiation, X-ray free electron lasers and beyond

2019 ◽  
Vol 377 (2147) ◽  
pp. 20180231 ◽  
Author(s):  
Tetsuya Ishikawa
Keyword(s):  
Synchrotron Radiation ◽  
Storage Ring ◽  
Free Electron ◽  
Continuous Wave ◽  
Transitional Period ◽  
Light Sources ◽  
X Rays ◽  
Free Electron Lasers ◽  
Beam Emittance ◽  
X Ray

The evolution of synchrotron radiation (SR) sources and related sciences is discussed to explain the ‘generation’ of the SR sources. Most of the contemporary SR sources belong to the third generation, where the storage rings are optimized for the use of undulator radiation. The undulator development allowed to reduction of the electron energy of the storage ring necessary for delivering 10 keV X-rays from the initial 6–8 GeV to the current 3 Gev. Now is the transitional period from the double-bend-achromat lattice-based storage ring to the multi-bend-achromat lattice to achieve much smaller electron beam emittance. Free electron lasers are the other important accelerator-based light sources which recently reached hard X-ray regime by using self-amplified spontaneous emission scheme. Future accelerator-based X-ray sources should be continuous wave X-ray free electron lasers and pulsed X-ray free electron lasers. Some pathways to reach the future case are discussed. This article is part of the theme issue ‘Fifty years of synchrotron science: achievements and opportunities’.

GENERATION OF X-RAYS WITH A HIGH DEGREE OF LONGITUDINAL COHERENCE

2007 ◽  
Vol 21 (03n04) ◽  
pp. 513-518
Author(s):  
ROBERT ROSSMANITH
Keyword(s):  
Synchrotron Radiation ◽  
Storage Rings ◽  
Light Sources ◽  
X Rays ◽  
X Ray ◽  
Electron Accelerators ◽  
Longitudinal Coherence ◽  
High Degree

Synchrotron radiation produced either in storage rings or SASE-FELs is longitudinally incoherent. In this paper a way to produce short longitudinally coherent X-ray pulses is discussed. In addition it is investigated if these sources can be modified to use them as light sources for vacuum electron accelerators.

scholarly journals Pixel detectors for diffraction-limited storage rings

2014 ◽  
Vol 21 (5) ◽  
pp. 1006-1010 ◽  
Author(s):  
Peter Denes ◽  
Bernd Schmitt
Keyword(s):  
Synchrotron Radiation ◽  
Storage Ring ◽  
Dynamic Range ◽  
State Of The Art ◽  
Storage Rings ◽  
X Rays ◽  
X Ray ◽  
Current State ◽  
Pixel Detectors ◽  
Radiation Sources

Dramatic advances in synchrotron radiation sources produce ever-brighter beams of X-rays, but those advances can only be used if there is a corresponding improvement in X-ray detectors. With the advent of storage ring sources capable of being diffraction-limited (down to a certain wavelength), advances in detector speed, dynamic range and functionality is required. While many of these improvements in detector capabilities are being pursued now, the orders-of-magnitude increases in brightness of diffraction-limited storage ring sources will require challenging non-incremental advances in detectors. This article summarizes the current state of the art, developments underway worldwide, and challenges that diffraction-limited storage ring sources present for detectors.

scholarly journals Latest Hybrid Pixel Detectors for increased q/t-resolution in SAXS

2014 ◽  
Vol 70 (a1) ◽  
pp. C882-C882
Author(s):  
Tilman Donath ◽  
Benjamin Lüthi ◽  
Clemens Schulze-Briese
Keyword(s):  
Data Quality ◽  
Spatial Resolution ◽  
Dynamic Range ◽  
Imaging Techniques ◽  
Sampling Point ◽  
X Rays ◽  
Pixel Detector ◽  
Pixel Size ◽  
Diffractive Imaging ◽  
X Ray

The PILATUS was the first Hybrid Pixel Detector available for SAXS. It has transformed data collection by its photon-counting technology, which enables noise-free X-ray detection with high dynamic range and excellent stability at high frame rates. These properties are essential for superior data quality in all scattering experiments, especially for optimal background correction when studying low-concentration samples. Besides optimal data quality at each sampling point, highest resolution is desired in most SAXS experiments both in q-range and in time. The newly developed EIGER pixel detector more than doubles the q-resolution that can be achieved when compared with PILATUS3 for the same sample-to-detector distance. EIGER features a pixel size of only 75 µm (in comparison: PILATUS3 has 172 µm). To characterize the spatial resolution of these detectors, point-spread functions were measured at the PTB laboratory at BESSY II, which show that the resolution is directly proportional to the pixel size with minimal cross talk between neighboring pixels. The EIGER 1M detector allows data acquisition at up to 3'000 frames per second. This enables unprecedented temporal resolution in time-resolved SAXS measurements and increases the speed of novel imaging techniques such as scanning SAXS/WAXS and coherent diffractive imaging applications, allowing images to be recorded faster or with higher spatial resolution. The design of the EIGER detector makes it vacuum compatible. Operation at low X-ray energies and correspondingly large scattering angles is another way of increasing q-resolution and also gives access to the lowest q data near the beam stop. In-vacuum detectors enable measurements with ultra-soft x-rays and thus high q-resolution. Moreover they optimize the data quality in scattering experiments by removing absorption and scatter caused from air and windows. An in-vacuum PILATUS 1M detector has been installed at the BESSY-2 FCM beamline and is applied for SAXS/GI-SAXS measurements at energies from 1.75 to 10 keV. For simultaneous SAXS/WAXS applications covering an even wider q-range, in-vacuum detectors with L-shaped detection surface are under development. These will detect the WAXS signal, while a clearance in the detector permits the direct beam to pass on to a SAXS detector placed at larger distance. These latest detector developments will be presented along with corresponding experimental results.

3-D Imaging of Deep-Fat Fried Chicken Nuggets Breading Coating Using X-Ray Micro-CT

2009 ◽  
Vol 5 (4) ◽  
Author(s):  
Akinbode A. Adedeji ◽  
Michael O. Ngadi
Keyword(s):  
Mass Transfer ◽  
Structural Properties ◽  
Structural Changes ◽  
Imaging Techniques ◽  
Micro Ct ◽  
Microstructural Properties ◽  
Chicken Nuggets ◽  
Frying Time ◽  
X Ray ◽  
Fried Foods

Food coatings are used to add value to deep-fat fried foods and to control heat and mass transfer during frying. They impart special characteristics such as crispiness and flavor to fried products while they also form a barrier to moisture and fat transfer during frying. Development of structure during frying plays an important role in defining the performance of batter/bread coatings. Food structural properties such as porosity have been associated with fat uptake in fried foods. A good understanding of the microstructural properties is necessary in order to produce high quality fried foods. X-ray micro-computed tomography (X-ray micro-CT) is a unique technique for imaging food non-invasively, requiring no or minimal sample preparation and 3-D rendition of high resolution images. The technique is capable of providing morphological details under a natural environment, which gives some advantages over the conventional imaging techniques such as microscopy. Study on chicken nuggets provided useful information relating frying conditions to structural changes in the breading-batter coating using X-ray micro-CT technique. Chicken nuggets were fried at 180°C for different frying durations after which the products were scanned using X-ray micro-CT. Images were reconstructed and analyzed, and 2-D and 3-D renditions of the coating images confirmed porosity changes with frying time. Numerical slicing of the 3-D images with image analysis software showed the degree of interconnectivity of pores, pore shape and pore count under different conditions of frying. The effect of frying time on microstructural parameters is significant. X-ray micro-CT shows great prospect in characterizing microstructural properties of foods especially coated fried products. This technique could be used in optimizing mass transfer during deep-fat frying by providing quantitative information on structural properties such as porosity, pore size distribution and pore connectivity.

scholarly journals Microsecond hydrodynamic interactions in dense colloidal dispersions probed at the European XFEL

IUCrJ ◽  
2021 ◽  
Vol 8 (5) ◽  
Author(s):  
Francesco Dallari ◽  
Avni Jain ◽  
Marcin Sikorski ◽  
Johannes Möller ◽  
Richard Bean ◽  
...  
Keyword(s):  
Soft Matter ◽  
Diffusion Constant ◽  
Correlation Spectroscopy ◽  
Fourth Generation ◽  
Photon Density ◽  
Light Sources ◽  
Pixel Detector ◽  
Time Resolved ◽  
X Ray ◽  
Scattering Volume

Many soft-matter systems are composed of macromolecules or nanoparticles suspended in water. The characteristic times at intrinsic length scales of a few nanometres fall therefore in the microsecond and sub-microsecond time regimes. With the development of free-electron lasers (FELs) and fourth-generation synchrotron light-sources, time-resolved experiments in such time and length ranges will become routinely accessible in the near future. In the present work we report our findings on prototypical soft-matter systems, composed of charge-stabilized silica nanoparticles dispersed in water, with radii between 12 and 15 nm and volume fractions between 0.005 and 0.2. The sample dynamics were probed by means of X-ray photon correlation spectroscopy, employing the megahertz pulse repetition rate of the European XFEL and the Adaptive Gain Integrating Pixel Detector. We show that it is possible to correctly identify the dynamical properties that determine the diffusion constant, both for stationary samples and for systems driven by XFEL pulses. Remarkably, despite the high photon density the only observable induced effect is the heating of the scattering volume, meaning that all other X-ray induced effects do not influence the structure and the dynamics on the probed timescales. This work also illustrates the potential to control such induced heating and it can be predicted with thermodynamic models.

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