X-ray Photon Correlation Spectroscopy Studies of Surfaces and Thin Films

2014 ◽  
Vol 26 (46) ◽  
pp. 7764-7785 ◽  
Author(s):  
Sunil K. Sinha ◽  
Zhang Jiang ◽  
Laurence B. Lurio
Keyword(s):  
Thin Films ◽  
Photon Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Photon Correlation ◽  
X Ray ◽  
Spectroscopy Studies

X-ray photon correlation spectroscopy in systems without long-range order: existence of an intermediate-field regime

2011 ◽  
Vol 19 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Karl Ludwig
Keyword(s):  
Photon Correlation Spectroscopy ◽  
Incident Beam ◽  
Correlation Spectroscopy ◽  
Far Field ◽  
Photon Correlation ◽  
X Ray ◽  
Detector Distance ◽  
Structural Correlation ◽  
Laser Sources ◽  
Spectroscopy Studies

Successful X-ray photon correlation spectroscopy studies often require that signals be optimized while minimizing power density in the sample to decrease radiation damage and, at free-electron laser sources, thermal impact. This suggests exploration of scattering outside the Fraunhofer far-field diffraction limitd2/λ \llR, wheredis the incident beam size, λ is the photon wavelength andRis the sample-to-detector distance. Here it is shown that, in an intermediate regimed2/λ >R\ggdξ/λ, where ξ is the structural correlation length in the material, the ensemble averages of the scattered intensity and of the structure factor are equal. Similarly, in the regimed2/λ >R\ggdξ(τ)/λ, where ξ(τ) is a time-dependent dynamics length scale of interest, the ensemble-averaged correlation functionsg1(τ) andg2(τ) of the scattered electric field are also equal to their values in the far-field limit. This broadens the parameter space for X-ray photon correlation spectroscopy experiments, but detectors with smaller pixel size and variable focusing are required to more fully exploit the potential for such studies.

scholarly journals From Femtoseconds to Hours–Measuring Dynamics over 18 Orders of Magnitude with Coherent X-rays

2021 ◽  
Vol 11 (13) ◽  
pp. 6179
Author(s):  
Felix Lehmkühler ◽  
Wojciech Roseker ◽  
Gerhard Grübel
Keyword(s):  
Time Scales ◽  
Free Electron Laser ◽  
Photon Correlation Spectroscopy ◽  
Signal To Noise Ratio ◽  
Coherent Scattering ◽  
Correlation Spectroscopy ◽  
X Rays ◽  
Photon Correlation ◽  
X Ray ◽  
Scattering Technique

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.

scholarly journals Grain Growth and Coarsening Dynamics in a Compositionally Asymmetric Block Copolymer Revealed by X-ray Photon Correlation Spectroscopy

2020 ◽  
Vol 53 (19) ◽  
pp. 8233-8243
Author(s):  
Ronald M. Lewis ◽  
Grayson L. Jackson ◽  
Michael J. Maher ◽  
Kyungtae Kim ◽  
Suresh Narayanan ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Grain Growth ◽  
Photon Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Photon Correlation ◽  
X Ray ◽  
Coarsening Dynamics

scholarly journals Atomic Migration Studies with X-Ray Photon Correlation Spectroscopy

2014 ◽  
Vol 2 ◽  
pp. 73-94 ◽  
Author(s):  
Markus Stana ◽  
Manuel Ross ◽  
Bogdan Sepiol
Keyword(s):  
Low Temperatures ◽  
Short Range ◽  
Short Range Order ◽  
Photon Correlation Spectroscopy ◽  
Condensed Matter ◽  
Correlation Spectroscopy ◽  
Atomic Scale ◽  
Photon Correlation ◽  
X Ray ◽  
Amorphous Systems

The new technique of atomic-scale X-ray Photon Correlation Spectroscopy (aXPCS) makesuse of a coherent X-ray beam to study the dynamics of various processes in condensed matter systems.Particularly atomistic migration mechanisms are still far from being understood in most of intermetallicalloys and in amorphous systems. Special emphasis must be given to the opportunity to measureatomistic diffusion at relatively low temperatures where such measurements were far out of reach withpreviously established methods. The importance of short-range order is demonstrated on the basis ofMonte Carlo simulations.

scholarly journals Distributed X-ray photon correlation spectroscopy data reduction using Hadoop MapReduce

2018 ◽  
Vol 25 (4) ◽  
pp. 1135-1143 ◽  
Author(s):  
Faisal Khan ◽  
Suresh Narayanan ◽  
Roger Sersted ◽  
Nicholas Schwarz ◽  
Alec Sandy
Keyword(s):  
Real Time ◽  
Photon Correlation Spectroscopy ◽  
Correlation Spectroscopy ◽  
Frame Rate ◽  
Computational Techniques ◽  
Complex Materials ◽  
Photon Correlation ◽  
X Ray ◽  
Wide Range ◽  
Recent Developments

Multi-speckle X-ray photon correlation spectroscopy (XPCS) is a powerful technique for characterizing the dynamic nature of complex materials over a range of time scales. XPCS has been successfully applied to study a wide range of systems. Recent developments in higher-frame-rate detectors, while aiding in the study of faster dynamical processes, creates large amounts of data that require parallel computational techniques to process in near real-time. Here, an implementation of the multi-tau and two-time autocorrelation algorithms using the Hadoop MapReduce framework for distributed computing is presented. The system scales well with regard to the increase in the data size, and has been serving the users of beamline 8-ID-I at the Advanced Photon Source for near real-time autocorrelations for the past five years.

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