Publications by authors named "Cornelia B Wunderer"
The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, results from the first megahertz-repetition-rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL are presented.
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- Researchers adapted single-shot ptychography to the XUV range and tested it at the FLASH facility at DESY, achieving high-resolution imaging of a test sample.
- Traditional ptychography is slow due to its scanning process and struggles to capture dynamic events, while single-shot techniques collect multiple overlapping diffraction patterns in one go.
- The new setup combines X-ray focusing optics with a special beam-splitting diffraction grating, enabling rapid imaging of extended samples at X-ray wavelengths.
In this paper the back-side-illuminated Percival 2-Megapixel (P2M) detector is presented, along with its characterization by means of optical and X-ray photons. For the first time, the response of the system to soft X-rays (250 eV to 1 keV) is presented. The main performance parameters of the first detector are measured, assessing the capabilities in terms of noise, dynamic range and single-photon discrimination capability.
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- The text discusses the need for advanced photon imaging detectors due to improvements in synchrotron radiation and free-electron lasers, emphasizing requirements like high frame rates and single-photon sensitivity.
- It highlights two key projects at DESY: the PERCIVAL CMOS-based soft X-ray imager, designed for high efficiency and large pixel count, and the AGIPD, a high-speed hybrid pixel detector aimed at single-pulse imaging at the European XFEL.
- The document reviews the concepts and statuses of both systems, shares recent results, and mentions other developments that the Photon Science Detector Group at DESY is working on.
Protein crystallization in cells has been observed several times in nature. However, owing to their small size these crystals have not yet been used for X-ray crystallographic analysis. We prepared nano-sized in vivo-grown crystals of Trypanosoma brucei enzymes and applied the emerging method of free-electron laser-based serial femtosecond crystallography to record interpretable diffraction data.
View Article and Find Full Text PDFX-ray free-electron lasers have enabled new approaches to the structural determination of protein crystals that are too small or radiation-sensitive for conventional analysis. For sufficiently short pulses, diffraction is collected before significant changes occur to the sample, and it has been predicted that pulses as short as 10 fs may be required to acquire atomic-resolution structural information. Here, we describe a mechanism unique to ultrafast, ultra-intense X-ray experiments that allows structural information to be collected from crystalline samples using high radiation doses without the requirement for the pulse to terminate before the onset of sample damage.
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