A 250 Hz fast shutter with flexible sampling schemes for low-dose XPCS experiments at beamline P10 at PETRA III

Low-dose X-ray photon correlation spectroscopy experiments on biological samples can be used to investigate the structure formation and underlying dynamics during phase separation, denaturation, and gelation. However, the use of intensive X-ray beams as an investigative tool is limited due to the susceptibility of biological samples to radiation-induced changes. XPCS in particular requires recording a series of high-frame-rate images to capture fast dynamics. In such cases, a fast X-ray shutter system is required to minimize beam damage to the samples by allowing a flexible delay between two images. Here we show how a fast (250 Hz) X-ray shutter system, built by the University of Siegen in close collaboration with DESY, improves low-dose XPCS capabilities at the P10 beamline at PETRA III. We found that by employing this shutter system in a logarithmic sampling scheme, the absorbed X-ray dose on the samples could be significantly decreased.