Adapted to the PETRA III P64 beamline, an X-ray reflectometer optimized for surface sensitive EXAFS experiments at grazing incidence with a time resolution in the 10 ms-range will be realized. The combination of the grazing incidence geometry providing the surface sensitivity together with the temporal resolution of the quick-scanning EXAFS monochromator will enable dynamic studies of all kinds of surface processes such as e.g. thin film growth, surface reactions in gaseous or liquid environments as well as electrocatalyis with a unique time resolution. Key importance has a rugged reflectometer sample stage, which is able to cope with heavy loads such as e.g. vacuum or preparation chambers while maintaining a high angular precision in the range of 0.001°, and furthermore a large distance between the basis of the reflectometer and its centre of rotation which is a prerequisite for the use of any in-situ equipment. We plan to realize a stable and massive cradle, that is able to house the sample environment of up to at least 100 kg, and a second rotation circle with a high precision goniometer to carry the detectors for the reflected beam and a reference sample. Additional fluorescence detectors with suited fast amplifier electronics will be employed as well, here we will try to adapt avalanche photodiodes for a fast fluorescence detection. For the analysis of the acquired surface-EXAFS data, specialized software will be developed, based on the experience of the team of the applicant and existing codes. This is of particular importance, since the amount of data recorded during time resolved EXAFS studies is a challenging task especially for the data analysis, which has be automatized.

Duration:
01.07.2019 – 30.06.2022

Project-leader:
Prof. Dr. D. Lützenkirchen-Hecht

Budget:
388.000 €