Vacuum UV spectroscopy setup at BESSY II
Spectroscopy is a really powerful measurement tool in the research field of Astrochemistry. For instance, planetary atmospheres as well as organic and inorganic samples exhibit well known spectroscopic signals making it possible to detect photochemical changes in those sample species. In planetary and space simulation experiments in our laboratory at Freie Universität Berlin we make use of different spectroscopy techniques, covering a wavelength range from 200nm up to 12000µm. To extend this wavelength range, measurements on an UV-beamline (120nm-250nm) at the synchrotron facility Bessy II in Berlin-Adlershof should be routinely included in the experimental process. An existing measurement setup should be customized to enable UV-spectroscopy measurements of astrochemical sample species as part of the preparation of an upcoming experiment on the International Space Station.
Based on an existing set up for sample measurement supplied by the Bessy II facility, a new design for a set up should be implemented. While all required parts have been purchased already and the geometrical dimensions are determined, the main objective of this work is the characterization of a space saving Photo-Diode detector (PD). In the previous setup a Photo Multiplier Detector (PMD) was utilized which can be used as a reference, as the new detector system should perform comparable or better in terms of its signal-to-noise ratio and reproducibility of measurement data.
The PMD of the previous measurement setup can be loaned from the Bessy II facility to have a reference available. Based on its performance, the PD should be implemented and characterized. The preparation will be done in the laboratories of Freie Universität Berlin. To mimicke the synchrotron radiation, a commercial UV-light source can be used. For energy resolved measurements, the UV light source can be combined with a UV-grating.