ID10: Coherent convergence

The ESRF’s ID10A beamline has pioneered the technique of X-ray photon correlation spectroscopy (XPCS). Here, coherent X-rays scattered from a disordered sample produce a grainy diffraction pattern called a “speckle” pattern that allows users to follow the dynamics of condensed-matter systems, such as the mixing and unmixing kinetics in alloys. Located a few metres downstream from ID10A, the ID10C station has recently enabled coherent X-ray diffraction imaging (CXDI) – a technique that provides nanoscale data about samples at higher resolutions than competing imaging techniques.

The ESRF’s ID10B branch, meanwhile, specialises in the applications of surface-sensitive techniques for studying the 2D structural organisation and slow kinetics in artificially or self-ordered soft-matter at interfaces, on scales ranging from a few tenths of a nanometre to several micrometres.

Following a significant €2 m refurbishment, the ID10 complex – previously known as the Troika I, II and III beamlines – will restart in June 2012 under the name “soft interfaces and coherent scattering” (SICS). ID10A/C and ID10B will be transformed into one beamline with two end stations working in 50% time-sharing mode. One station (SICS-CS) will be devoted to coherent scattering, namely XPCS and CXDI, while the other (SICS-LSIS) will concern liquid surfaces and interfaces scattering based on X-ray reflectivity and grazing incidence scattering. Each station will benefit from independent optics and instrumentation optimised for each of the techniques, and will be served by two different silicon monochromators, one replacing ID10B’s underperforming semi-transparent diamond monochromator.

“The refurbished CS beamline will keep us among the leaders in the field,” says CS scientist-in-charge Yuriy Chushkin. Compared with the previous ID10 configuration, the new CS station will operate with a beam intensity twice as large and better coherence preservation, while an extended sample-detector distance will improve the oversampling of speckle patterns as required for CXDI. Meanwhile, the LSIS station, explains scientist-in-charge Oleg Konovalov, has obtained a factor 10 increase in the flux, a larger energy range (8–30 keV), an anomalous scattering option and a faster liquid reflectivity set-up. This will give the ESRF a leading position in studies of buried interfaces, coupling a fine-beam focusing with a small-beam divergence and offering the possibility to probe shorter timescales.

Matthew Chalmers

This article appeared in ESRFnews, March 2012. 

To register for a free subscription and to rapidly receive the current issue, please go to: ESRFNews Digital Edition Subscription

Top image: Speckle pattern from unstained Deinococcus Radiodurans bacteria obtained at ID10C.