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

2013 ◽  
Vol 21 (1) ◽  
pp. 264-267 ◽  
Author(s):  
Chung-Jong Yu ◽  
Hae Cheol Lee ◽  
Chan Kim ◽  
Wonsuk Cha ◽  
Jerome Carnis ◽  
...  

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.

2010 ◽  
Vol 81 (2) ◽  
pp. 026103 ◽  
Author(s):  
Ik-Jae Lee ◽  
Chung-Jong Yu ◽  
Young-Duck Yun ◽  
Chae-Soon Lee ◽  
In Deuk Seo ◽  
...  

2011 ◽  
Vol 44 (1) ◽  
pp. 200-212 ◽  
Author(s):  
F. Zhang ◽  
A. J. Allen ◽  
L. E. Levine ◽  
J. Ilavsky ◽  
G. G. Long ◽  
...  

This paper describes the development of ultra-small-angle X-ray scattering–X-ray photon correlation spectroscopy (USAXS–XPCS). This technique takes advantage of Bonse–Hart crystal optics and is capable of probing the long-time-scale equilibrium and non-equilibrium dynamics of optically opaque materials with prominent features in a scattering vector range between those of dynamic light scattering and conventional XPCS. Instrumental parameters for optimal coherent-scattering operation are described. Two examples are offered to illustrate the applicability and capability of USAXS–XPCS. The first example concerns the equilibrium dynamics of colloidal dispersions of polystyrene microspheres in glycerol at 10, 15 and 20% volume concentrations. The temporal intensity autocorrelation analysis shows that the relaxation time of the microspheres decays monotonically as the scattering vector increases. The second example concerns the non-equilibrium dynamics of a polymer nanocomposite, for which it is demonstrated that USAXS–XPCS can reveal incipient dynamical changes not observable by other techniques.


2021 ◽  
Vol 11 (13) ◽  
pp. 6179
Author(s):  
Felix Lehmkühler ◽  
Wojciech Roseker ◽  
Gerhard Grübel

X-ray photon correlation spectroscopy (XPCS) enables the study of sample dynamics between micrometer and atomic length scales. As a coherent scattering technique, it benefits from the increased brilliance of the next-generation synchrotron radiation and Free-Electron Laser (FEL) sources. In this article, we will introduce the XPCS concepts and review the latest developments of XPCS with special attention on the extension of accessible time scales to sub-μs and the application of XPCS at FELs. Furthermore, we will discuss future opportunities of XPCS and the related technique X-ray speckle visibility spectroscopy (XSVS) at new X-ray sources. Due to its particular signal-to-noise ratio, the time scales accessible by XPCS scale with the square of the coherent flux, allowing to dramatically extend its applications. This will soon enable studies over more than 18 orders of magnitude in time by XPCS and XSVS.


2012 ◽  
Vol 46 (1) ◽  
pp. 234-241 ◽  
Author(s):  
Chae Un Kim ◽  
Jennifer L. Wierman ◽  
Richard Gillilan ◽  
Enju Lima ◽  
Sol M. Gruner

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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