Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 16: Poster Monday: Ultrafast Processes 1
O 16.3: Poster
Montag, 5. September 2022, 18:00–20:00, P4
Numerous Improvements on Ultrafast Pump-Probe RHEED Experiment — •Jonas Fortmann1, Christian Brand1, Thorben Groven1, Mohammad Tajik1, Michael Horn-von Hoegen1, and Thomas Duden2 — 1Department of Physics and Center for Nanointegration CENIDE, University of Duisburg-Essen, Lotharstraße 1, 47057 Duisburg — 2Construction office, Mustangweg 17, D-33649, Bielefeld
During the last year, major improvements have been made to our ultrafast time-resolved reflection high energy electron diffraction (tr-RHEED) experiment. In particular, the previous detection unit consisting of a multichannel plate and a cooled CCD camera has been replaced by a single electron sensitive CMOS based camera (TVIPS TemCam XF-416), which allows spot profile analysis with its superior resolution and signal-to-noise ratio and no blooming. Flatfielding of the detector is achieved with a home-built electron source at 20 keV accompanied by an external EM-deflection unit. In addition, the 80 fs-laser pump pulse (λ = 800 nm) has been upgraded with an optical parametric amplifier (Topas Prime) that allows excitation of the sample’s surface at 1.16−2.60 µm in future experiments. Re-routing of the beamline has shortened the beam paths by ∼1.5 m and saved half of the mirrors, which provides higher beam stability. Also the third harmonic generation (THG) stage for electron generation in the Au film photocathode has been optimized. A new lab software has been established on the basis of TANGO controls. First experimental data with the new setup are shown.