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For the investigation of ultrafast processes in the energy domain the optical laser pump nir-vis probe spectroscopy is a useful tool [1]. Two pump-probe spectrometers were designed. We will present the design of a time resolved spectrometer (TRABS) with microfocusing unit for the investigation of micro-objects like crystals. The measurements with this setup allow for a deeper insight into the photoinduced dynamics of solid state samples and can be combined with time resolved x-ray diffraction studies carried out at synchrotron facilities. For measurements at the FLASH facility (DESY) a time resolved reflection spectrometer and a compact vacuum cell were designed. In this setup the optical laser beam can be used as a pump or as a probe unit. In the vacuum cell solid state samples and liquid samples in a micro liquid jet can be used [2]. With the optical laser as probe, radiation damage can be monitored. An example for radiation damage is the generation of solvated electrons in water. In the homebased setup the solvated electrons synthesized via multiphoton absorption at 400nm [3]. The setup is built as an entity for FLASH\optical Laser pump\ FLASH\optical laser probe unit. Ultrafast time resolved diffraction experiments can also be investigated with that setup. First demonstration experiments have been performed with a TR soft-x-ray plasmasource [4]. [1] J. W. Shelton and J. Armstrong, IEEE J. Quantum Electron., QE3, (1967), 696. [2] M. Faubel, Schlemmer S., Toennies J.P., Z. Phys., D10, (1988), 269-277. [3] J.Z. Zhang et al., Chem. Phys. Letters, 231, (1994) 504. [4] Peth C., Quevedo W., Techert S., submitted. |
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