Implementation of the quick-scanning EXAFS technique at DELTA beamline 10

The quick-scanning EXAFS technique has been implemented at the materials science beamline 10 at the 1.5 GeV electron storage ring DELTA employing a multipole wiggler as the X-ray source. A mechanically stable Si(111) channel-cut monochromator was used for fast continuous energy scans in the range from ca. 4.5 keV to 14 keV covering the K-edges from Ti to Br, and the L-edges from Cs to Bi, with a simultaneous read-out of the detectors, i.e., ionization chambers and photodiodes for transmission and fluorescence mode measurements. The experiments have shown that high-quality EXAFS data can be achieved on time scales of slightly more than 30 seconds for a high-quality EXAFS scan extending over 1500 eV and more, while near edge XANES data covering about 100 eV only take 1-2 seconds with a high repetition rate scanning up-and downwards in energy. We will present a detailed quantitative evaluation of Quick-EXAFS experiments of metal reference foils revealing no systematic variations of the fit quality, the determined distances of the nearest neighbors, the value of the amplitude reduction factor and the disorder parameters for the first shells.
Thus, the new experimental capabilities allow extended scans of multi-element samples such as high-entropy-alloys (HEA) encompassing several absorption edges within some few minutes acquisition time only. We will describe experimental setup, discuss the collected data and present some very first examples, where the new capabilities are demonstrated. Finally we will give an outline for future experiments.