C. Wunderer
A5078015324- Particle Detector Development and Performance
- Gamma-ray bursts and supernovae
- Medical Imaging Techniques and Applications
- Nuclear Physics and Applications
- Advanced X-ray Imaging Techniques
- Radiation Detection and Scintillator Technologies
- Astrophysical Phenomena and Observations
- Astrophysics and Cosmic Phenomena
- Advanced X-ray and CT Imaging
- Particle Accelerators and Free-Electron Lasers
- Advanced Electron Microscopy Techniques and Applications
- CCD and CMOS Imaging Sensors
- Advanced Semiconductor Detectors and Materials
- Radiation Therapy and Dosimetry
- Enzyme Structure and Function
- X-ray Spectroscopy and Fluorescence Analysis
- Stellar, planetary, and galactic studies
- Solar and Space Plasma Dynamics
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Dark Matter and Cosmic Phenomena
- Advancements in Photolithography Techniques
- Crystallography and Radiation Phenomena
- Geophysics and Gravity Measurements
Deutsches Elektronen-Synchrotron DESY
2014-2024
Center for Free-Electron Laser Science
2015-2024
Universität Hamburg
2015-2024
Uppsala University
2022
Diamond Light Source
2016
University of California, Berkeley
2004-2010
Max Planck Institute for Extraterrestrial Physics
2001-2008
Space Science Institute
2006
University of California System
2006
Berkeley College
2005
SPI is a high spectral resolution gamma-ray telescope on board the ESA mission INTEGRAL (International Gamma Ray Astrophysics Laboratory). It consists of an array 19 closely packed germanium detectors surrounded by active anticoincidence shield BGO. The imaging capabilities instrument are obtained with tungsten coded aperture mask located 1.7 m from Ge array. fully field-of-view , partially field view amounts to and angular . energy range extends 20 keV 8 MeV typical 2.5 at 1.3 MeV. Here we...
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 report experimental results on x-ray diffraction of quantum-state-selected and strongly aligned ensembles the prototypical asymmetric rotor molecule 2,5-diiodobenzonitrile using Linac Coherent Light Source. The experiments demonstrate first steps toward a new approach to diffractive imaging distinct structures individual, isolated gas-phase molecules. confirm several key ingredients single experiments: abilities detect count individual scattered photons in shot data, deliver...
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...
Aims.Gamma-ray line emission from radioactive decay of 60Fe provides constraints on nucleosynthesis in massive stars and supernovae.
<?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"...
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 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 SPI instrument has been launched on-board the INTEGRAL observatory on October 17, 2002. is a spectrometer devoted to sky observation in 20 keV–8 MeV energy range using 19 germanium detectors. performance of cryogenic system nominal and allows cool kg down 85 K with comfortable margin. resolution whole camera 2.5 keV at 1.1 MeV. This degrades time due particle irradiation space. We show that annealing process recovery initial performance. anticoincidence shield works as expected, low...
The first DSSC 1-Mpixel camera became available at the European XFEL (EuXFEL) in Hamburg area February 2019.It was successfully tested, installed, and commissioned Spectroscopy Coherent Scattering Instrument.DSSC is a high-speed, large-area, 2-D imaging detector system optimized for photon science applications energy range between
We describe femtosecond X-ray diffraction data sets of viruses and nanoparticles collected at the Linac Coherent Light Source.The establish first large benchmark for coherent methods freely available to public, bolster development algorithms that are essential developing this novel approach as a useful imaging technique.Applications 2D reconstructions, orientation classification finally 3D by assembling patterns into volume.
Abstract PERCIVAL is a novel soft X-ray detection system designed for the needs of modern microscopy. By integrating it into TwinMic end-station at Elettra Sincrotrone Trieste, we conducted an exploratory computational microscopy experiment on biological samples, aiming evaluating entire in real use-case scenario. We present methodology to convert RAW data and our high-resolution image reconstructions.
On Oct. 17, 2002, the ESA INTEGRAL observatory was launched into a highly elliptical orbit. SPI, high resolution Ge spectrometer covering an energy range of 20–8000 keV, is one its two main instruments. We use data recorded early in mission (i.e. March 2003) to characterize instrumental background, particular many gamma-ray lines produced by cosmic-ray interactions instrument and spacecraft materials. More than 300 spectral features are observed, for about 220 which we provide...
Three calibration campaigns of the spectrometer SPI have been performed before launch in order to determine instrument characteristics, such as effective detection area, spectral resolution and angular resolution. Absolute determination area has obtained from simulations measurements. At 1 MeV, is 65 cm^2 for a point source on optical axis, ~2.3 keV. The better than 2.5 deg separation capability about deg. Some temperature dependant parameters will require permanent in-flight calibration.
In this paper we discuss the methods developed for production of INTEGRAL/SPI instrument response. The response files were produced using a suite Monte Carlo simulation software at NASA/GSFC based on GEANT-3 package available from CERN. also required development detailed computer mass model SPI. We our extensive investigations into to reduce both computation time and storage requirements SPI corrections simulated comparison ground inflight calibration data with MGEANT simulations.
The Nuclear Compton Telescope (NCT) is a balloon-borne telescope designed for the study of astrophysical sources in soft gamma-ray regime (200 keV–20 MeV). NCT's 10 high-purity germanium crossed-strip detectors measure deposited energies and three-dimensional positions interactions sensitive volume, this information used to restrict initial photon circle on sky using scatter technique. Thus NCT able perform spectroscopy, imaging, polarization analysis sources. one next generation...
The emergence of femtosecond diffractive imaging with X-ray lasers has enabled pioneering structural studies isolated particles, such as viruses, at nanometer length scales.However, the issue missing low frequency data significantly limits potential to reveal sub-nanometer details micrometer-sized samples.We have developed a new technique dark-field coherent simultaneously overcome and enable us harness unique contrast mechanisms available in microscopy.Images airborne particulate matter...
Since the discovery of cosmological origin gamma-ray bursts (GRBs), there has been growing interest in using these transient events to probe quantum gravity energy scale range 1016-1019 GeV, up Planck mass scale. This can manifest itself through a measurable modification electromagnetic radiation dispersion relation for high-energy photons originating from distances. We have used data GRB 2002 December 6 (GRB 021206) place an upper bound on speed light. The limit first-order effects derived...
We performed a spectroscopic study of the 1809 keV gamma-ray line from 26Al decay in Galaxy using SPI imaging spectrometer with its high-resolution Ge detector camera on INTEGRAL observatory. analyzed observations first two mission years, fitting spectra all 7130 telescope pointings narrow energy bins to models instrumental background and sky. Instrumental is estimated independent tracers cosmic-ray activation. The shape signal compared response extract width celestial line. detect at...