Ultrafast x-ray diffraction (UXRD) at the KMC-3 XPP beamline at the synchrotron radiation source BESSY II operated at the Helmholtz-Center Berlin by the joint research group ultrafast dynamics:
Our endstation allows for optical excitation of the samples with femtosecond laser pulses and resolving lattice dynamics via reciprocal space mapping (RSM) with 100 ps time resolution. To record the high-resolution RSMs we utilize a 4-cycle goniometer in combination with a CMOS-based single-photon counting area detector PILATUS 100k (DECTRIS).
The sample environment includes a closed-cycle Helium cryostat allowing for temperature control down to 20 K. The sample holder can be equipped with an automated needle contact for applying voltage pulses to the samples.
Further details on the beamline and the KMC-3 XPP endstation can be found in the following publication:
Rössle et al., J. Synch. Rad 28, 1 (2021).
In addition to the existing Si x-ray monochromator with an energy resolution of 1:5000, we are implementing a multilayer monochromator with 1:100 bandwidth to increase the available x-ray flux. The figure shows the multilayer monochromator and the vacuum chamber that houses a 4-circle goniometer with cryogenic cooling.