Ultrafast Laser Pump X-Ray Probe Experiments By Means Of Asynchronous Sampling

A high time resolution in the picosecond range is required for the time-domain investigatgion of phonon dynamics in crystalline systems. Following a recently developed scheme n the visible spectrum, this resolution can be achieved by a method called asychrounous optical x-ray sampling (ASOXS). A pulsed femtosecond laser with high repetition rate is synchronized to the electron bunches in a storage ring. A slight frequencey detuning changes the mutual delay continuously resulting in a time-domain x-ray sampling of the laser-excited system. At the synchtron radiation source ANKA a machine mode with low momemtrum campaction factor alpha(c) is available, which delivers ultra-short x-ray pulses int the picosecond range.