H. Graafsma
A5063687507- Advanced X-ray Imaging Techniques
- Particle Detector Development and Performance
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Radiation Detection and Scintillator Technologies
- CCD and CMOS Imaging Sensors
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Electron Microscopy Techniques and Applications
- Enzyme Structure and Function
- X-ray Diffraction in Crystallography
- Electron and X-Ray Spectroscopy Techniques
- Advancements in Photolithography Techniques
- Particle Accelerators and Free-Electron Lasers
- Advanced Semiconductor Detectors and Materials
- Solid-state spectroscopy and crystallography
- Physics of Superconductivity and Magnetism
- Nuclear Physics and Applications
- Electronic and Structural Properties of Oxides
- Acoustic Wave Resonator Technologies
- High-pressure geophysics and materials
- Magnetic and transport properties of perovskites and related materials
- Crystallography and Radiation Phenomena
- Diamond and Carbon-based Materials Research
- Zeolite Catalysis and Synthesis
- Nonlinear Optical Materials Research
Deutsches Elektronen-Synchrotron DESY
2015-2024
Center for Free-Electron Laser Science
2015-2024
Mid Sweden University
2015-2024
Universität Hamburg
2013-2024
Massachusetts Institute of Technology
2016
Hamburg Institut (Germany)
2011-2014
Vifor Pharma (Switzerland)
2013
University of Bonn
2013
European Synchrotron Radiation Facility
1999-2010
European X-Ray Free-Electron Laser
2009
We demonstrate the use of an X-ray free electron laser synchronized with optical pump to obtain diffraction snapshots from photoactivated states large membrane protein complexes in form nanocrystals flowing a liquid jet.Light-induced changes Photosystem I-Ferredoxin co-crystals were observed at time delays 5 10 µs after excitation.The result correlates microsecond kinetics transfer I ferredoxin.The undocking process that follows leads rearrangements crystals will terminally lead...
The plasma dynamics of single mesoscopic Xe particles irradiated with intense femtosecond x-ray pulses exceeding ${10}^{16}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ from the Linac Coherent Light Source free-electron laser are investigated. Simultaneous recording diffraction patterns and ion spectra allows eliminating influence focal volume intensity particle size distribution. data show that for clusters illuminated pulses, highly charged ionization fragments in a narrow distribution...
Abstract The new European X-ray Free-Electron Laser is the first free-electron laser capable of delivering pulses with a megahertz inter-pulse spacing, more than four orders magnitude higher previously possible. However, to date, it has been unclear whether would indeed be possible measure high-quality diffraction data at pulse repetition rates. Here, we show that structures can obtained using currently available operating conditions XFEL. We present two complete sets, one from well-known...
X-ray free-electron lasers deliver intense femtosecond pulses that promise to yield high resolution diffraction data of nanocrystals before the destruction sample by radiation damage. Diffraction intensities lysozyme collected at Linac Coherent Light Source using 2 keV photons were used for structure determination molecular replacement and analyzed damage as a function pulse length fluence. Signatures are observed short 70 fs. Parametric scaling in conventional crystallography does not...
Pilatus is a silicon hybrid pixel detector system for detecting X-rays in single photon counting mode. The PILATUS II chip, fabricated radiation tolerant design with standard 0.25 mum CMOS process, was used to construct multichip modules size of 84 times 34 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> comprising 94'965 pixels. All calibrations and characterizations were carried out monochromatic from synchrotron source. In order...
<?Pub Dtl=""?> We present the development of DSSC instrument: an ultra-high speed detector system for new European XFEL in Hamburg. The will be able to record X-ray images with a maximum frame rate 4.5 MHz. is based on silicon pixel sensor DEPFET as central amplifier structure and has detection efficiency close 100% X-rays from 0.5 keV up 10 keV. have size approximately 210 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The Adaptive Gain Integrating Pixel Detector (AGIPD) is an X-ray imager, custom designed for the European Free-Electron Laser (XFEL). It a fast, low-noise integrating detector, with adaptive gain amplifier per pixel. This has equivalent noise of less than 1 keV when detecting single photons and, switched into another state, dynamic range more 10 4 12 keV. In burst mode system able to store 352 images while running at up 6.5 MHz, which compatible 4.5 MHz frame rate XFEL. AGIPD was installed...
X-ray crystallography is one of the main methods to determine atomic-resolution 3D images whole spectrum molecules ranging from small inorganic clusters large protein complexes consisting hundred-thousands atoms that constitute macromolecular machinery life. Life not static, and unravelling structure dynamics most important reactions in chemistry biology essential uncover their mechanism. Many these reactions, including photosynthesis which drives our biosphere, are light induced occur on...
Abstract The ever-increasing brightness of synchrotron radiation sources demands improved X-ray optics to utilise their capability for imaging and probing biological cells, nanodevices functional matter on the nanometer scale with chemical sensitivity. Here we demonstrate focusing a hard beam an 8 nm focus using volume zone plate (also referred as wedged multilayer Laue lens). This lens was constructed new deposition technique that enabled independent control angle thickness diffracting...
A modular system of techniques and software has been developed for the calibration correction intensity linearity, uniformity response, spatial distortion, image plate decay. With Molecular DynamicsTM Imaging Plate scanner shown to give comparable results MarResearchTM scanner. The ESRF x-ray intensifier/charge-coupled device detectors inherently cause large response distortions, successful data analysis depends on correction. Results synchrotron radiation experiments are presented.
Single-particle experiments using X-ray Free Electron Lasers produce more than 10(5) snapshots per hour, consisting of an admixture blank shots (no particle intercepted), and exposures one or particles. Experimental data sets also often contain unintentional contamination with different species. We present unsupervised method able to sort experimental without recourse templates, specific noise models, user-directed learning. The results show 90% agreement manual classification.
The source characteristics of the European XFEL and planned experimental facilities that are relevant for X-ray detectors presented, requirements 2-dimensional Detectors stated explained. It is clear that, although these will evolve with time, they demand new detector concepts to be developed. Three development projects have been initiated by XFEL, each using a conceptually different approach meet stringent requirements. basic principles used in briefly presented.
The resolution of single-shot coherent diffractive imaging at X-ray free-electron laser facilities is limited by the low signal-to-noise level diffraction data high scattering angles.The iterative reconstruction methods, which phase a continuous pattern to produce an image, must be able extract information from these weak signals obtain best quality images.Here we show how modify methods improve tolerance noise.The method demonstrated with hybrid input-output on both simulated and patterns...
The large penetration power of high-energy X-rays (>60 keV) raises interesting prospects for new types structural characterizations polycrystalline materials. It becomes possible in a non-destructive manner to perform local studies, within the bulk material, fundamental materials physics properties: grain orientations, strain, dislocation densities etc. In favourable cases these properties may be mapped three dimensions with spatial resolution that matches individual grains. Imbedded volumes...