FEL Physics and Instrumentation Development
Free-electron lasers such as FLASH at DESY in Hamburg and LCLS in Stanford provide ultra-short, coherent XUV- and x-ray pulses with unprecedented brilliance.
We develope new methods and new instrumentation to characterize the properties of these FEL sources and to study ultrafast dynamics and nonlinear processes with time-resolved X-ray spectroscopy.
FLASH - Split and Delay Line
The Free electron LASer at DESY in Hamburg (FLASH) is a source for intense, coherent, ultra-short an tuneable soft x-ray radiation. It has opened the door to study multiphoton, nonlinear processes as well as ultra-fast dynamics of atoms and in highly correlated systems.
To further enhance the possbibilities of FLASH a XUV split-and-delay line (Mach-Zehnder type autocorrelator) has been developed and in the framework of the GrK 1355 „Physik mit neuartigen kohärenten Strahlungsquellen“ been implemented and characterized in the plane grating monochromator beamline PG2. This device is able to split the ultra short XUV pulses and delay them at least up to 5.1ps with a hundred attosecond reproducability. It is now possbile to study ultrafast XUV induced dynamics in a site-selective way.
This device can be used to study the temporal coherence properties of FLASH at various wavelengths for different machine setups. Furthermore, the PG2 beamline allows to study the temporal coherence properties energy resolved at the expense of lengthening the pulses.
[1] Rev. Sci. Instrum. 81, 043107 (2010)
