Stefan P. Hau‐Riege
A5091369247- Advanced X-ray Imaging Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Electron Microscopy Techniques and Applications
- Crystallography and Radiation Phenomena
- Laser-Plasma Interactions and Diagnostics
- Particle Accelerators and Free-Electron Lasers
- Copper Interconnects and Reliability
- High-pressure geophysics and materials
- Advanced Surface Polishing Techniques
- Semiconductor materials and devices
- Integrated Circuits and Semiconductor Failure Analysis
- Electron and X-Ray Spectroscopy Techniques
- Laser Material Processing Techniques
- Enzyme Structure and Function
- Ion-surface interactions and analysis
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Diamond and Carbon-based Materials Research
- Electronic Packaging and Soldering Technologies
- Advanced X-ray and CT Imaging
- Advancements in Photolithography Techniques
- Advanced Chemical Physics Studies
- Laser-Matter Interactions and Applications
- Medical Imaging Techniques and Applications
- Photonic and Optical Devices
Lawrence Livermore National Laboratory
2014-2023
SLAC National Accelerator Laboratory
2007-2010
Czech Academy of Sciences, Institute of Physics
2009
Uppsala University
2007-2009
Deutsches Elektronen-Synchrotron DESY
2009
Toneyama National Hospital
2008
Osaka University
2008
Northern Illinois University
2008
Stanford Synchrotron Radiation Lightsource
2007
Lawrence Berkeley National Laboratory
2004
A solution to the inversion problem of scattering would offer aberration-free diffraction-limited three-dimensional images without resolution and depth-of-field limitations lens-based tomographic systems. Powerful algorithms are increasingly being used act as lenses form such images. Current image reconstruction methods, however, require knowledge shape object low spatial frequencies unavoidably lost in experiments. Diffractive imaging has thus previously been increase obtained by other...
Coherent x-ray diffraction microscopy is a method of imaging nonperiodic isolated objects at resolutions limited, in principle, by only the wavelength and largest scattering angles recorded. We demonstrate with high resolution all three dimensions, as determined quantitative analysis reconstructed volume images. These images are retrieved from three-dimensional data using no priori knowledge about shape or composition object, which has never before been demonstrated on object. also construct...
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...
We present results from experiments at the Linac Coherent Light Source (LCLS) demonstrating that serial femtosecond crystallography (SFX) can be performed to high resolution (~2.5 Å) using protein microcrystals deposited on an ultra-thin silicon nitride membrane and embedded in a preservation medium room temperature. Data acquired acquisition rate x-ray free electron laser sources overcome radiation damage, while sample consumption is dramatically reduced compared flowing jet methods....
Intense femtosecond x-ray pulses from free-electron laser sources allow the imaging of individual particles in a single shot. Early experiments at Linac Coherent Light Source (LCLS) have led to rapid progress field and, so far, coherent diffractive images been recorded biological specimens, aerosols, and quantum systems with few-tens-of-nanometers resolution. In March 2014, LCLS held workshop discuss scientific technical challenges for reaching ultimate goal atomic resolution single-shot...
Structural switch for fast switching Phase-change materials are important computer memory. They can quickly from glassy to crystalline using a thermal pulse and then lock in that structure long time at lower temperature. Zalden et al. probed the underlying atomic of two phase-change during this ultrafast x-rays simulations (see Perspective by Rao ). A liquid-liquid phase transition both allowed high temperatures. The lower-temperature glass locks structure, allowing long-term memory storage....
In nanotechnology, strategies for the creation and manipulation of nanoparticles in gas phase are critically important surface modification substrate-free characterization. Recent coherent diffractive imaging with intense femtosecond X-ray pulses has verified capability single-shot nanoscale objects at suboptical resolutions beyond radiation-induced damage threshold. By intercepting electrospray-generated particles a single 15 soft-X-ray pulse, we demonstrate specimen free flight first time,...
Very short and intense x-ray pulses can be used for diffraction imaging of single biological molecules. Inevitably, absorption initiates damage that degrades the molecule's image. This paper presents a continuum model physics leads to when small particle absorbs large dose. The main processes are found ionization Coulomb-force driven atomic motion. Trapping electrons, Debye shielding, nonuniform collisional all have significant effect on overall kinetics.
Abstract A two‐step machine learning approach to monitoring laser powder bed fusion (LPBF) additive manufacturing is demonstrated that enables on‐the‐fly assessments of track welds. First, in situ video melt pool data acquired during LPBF labeled according the (1) average and (2) standard deviation individual width also (3) whether or not continuous, measured postbuild through an ex height map analysis algorithm. This procedure generates three ground truth datasets for supervised learning....
Proteins that contain metal cofactors are expected to be highly radiation sensitive since the degree of X-ray absorption correlates with presence high-atomic-number elements and energy. To explore effects local damage in serial femtosecond crystallography (SFX), Clostridium ferredoxin was used as a model system. The protein contains two [4Fe-4S] clusters serve probes for radiation-induced electronic structural changes. High-dose room-temperature SFX datasets were collected at Linac Coherent...
The soft x-ray materials science instrument is the second operational beamline at linac coherent light source free electron laser. operates with a photon energy range of 480-2000 eV and features grating monochromator as well bendable refocusing mirrors. A broad experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated systems, matter under extreme conditions, laboratory astrophysics. Preliminary commissioning...
Ultralow density polymers, metals, and ceramic nanofoams are valued for their high strength-to-weight ratio, surface area, insulating properties ascribed to structural geometry. We obtain the labrynthine internal structure of a tantalum oxide nanofoam by x-ray diffractive imaging. Finite-element analysis from reveals mechanical consistent with bulk samples diffusion-limited cluster aggregation model, while excess mass on nodes discounts dangling fragments hypothesis percolation theory.
A linear accelerator based source of coherent radiation, FLASH (Free-electron LASer in Hamburg) provides ultra-intense femtosecond radiation pulses at wavelengths from the extreme ultraviolet (XUV; λ<100nm) to soft X-ray (SXR; λ<30nm) spectral regions.25-fs 32-nm were used determine ablation parameters PMMA -poly (methyl methacrylate).Under these irradiation conditions attenuation length and threshold found be (56.9±7.5)nm ~2 mJ•cm -2 , respectively.For a second wavelength 21.7 nm, was...
Short and intense x-ray pulses may be used for atomic-resolution diffraction imaging of single biological molecules. Radiation damage a low signal-to-noise ratio impose stringent pulse requirements. In this Letter, we describe methods decreasing the improving signal by encapsulating molecule in sacrificial layer (tamper) that reduces atomic motion postprocessing pulse-averaged pattern to correct ionization damage. Simulations show these greatly improve image quality.
We present the x-ray optical design of soft materials science instrument at Linac Coherent Light Source, consisting a varied line-spaced grating monochromator and Kirkpatrick-Baez refocusing optics. Results from commissioning are shown. A resolving power 3000 was achieved, which is within factor two goal.