[Zurück]

D. Rath, J. Pavelec, G. Parkinson, M. Schmid, U. Diebold:
"Design of an IRAS Setup to Investigate Adsorbates on Metal-Oxide Single Crystals";
Poster: DPG-Frühjahrstagung (DPG Spring Meeting) of the Surface Science Division, SurfaceScience21, virtual; 01.03.2021.

The IRAS system GRISU (GRazing incident Infrared absorption Spectroscopy Unit) was developed for investigations in the research field of single atom catalysis [1]. It combines the commercially available FTIR spectrometer Bruker Vertex 80v with an UHV chamber [2]. GRISU features five mirrors for beam guidance placed in HV and UHV environment. The development was concentrated to optimise the system´s performance, flexibility and usability resulting in a small controllable focal-spot diameter (3 mm) on the sample, different optical apertures, and motorised optical components. The simulated system (done with a ray tracing program and a simplified spectrometer model) shows an efficiency of 13 %, i.e. 13 % of the radiation passing through the first aperture (Ø 6 mm) after the IR source in the FTIR spectrometer reaches the detector after being reflected from the molecular beam spot on the sample. Compared to a commercially available system with two parabolic mirrors with a focal length of 500 mm, this is higher by a factor of about 60. All the optical components are mounted precisely in respect to each other to ensure the high performance requirement also after long term use.