A5052297966- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Advanced X-ray Imaging Techniques
- Laser-Matter Interactions and Applications
- High-pressure geophysics and materials
- X-ray Spectroscopy and Fluorescence Analysis
- Laser Material Processing Techniques
- Crystallography and Radiation Phenomena
- Ion-surface interactions and analysis
- Laser Design and Applications
- Plasma Diagnostics and Applications
- Diamond and Carbon-based Materials Research
- Thermography and Photoacoustic Techniques
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Force Microscopy Techniques and Applications
- Atomic and Subatomic Physics Research
- Electronic and Structural Properties of Oxides
- Advanced Electron Microscopy Techniques and Applications
- Enzyme Structure and Function
- Advanced X-ray and CT Imaging
- Spectroscopy and Quantum Chemical Studies
- Mass Spectrometry Techniques and Applications
Friedrich Schiller University Jena
2015-2024
Helmholtz Institute Jena
2014-2023
GSI Helmholtz Centre for Heavy Ion Research
2017-2022
Instituto de Óptica "Daza de Valdés"
2021
University of California, Berkeley
2017
Schiller International University
1995-2011
Max Planck Institute of Quantum Optics
2001-2010
École Polytechnique
1995-2008
Centre National de la Recherche Scientifique
1998-2008
Laboratoire pour l'utilisation des lasers intenses
1995-2008
The generation of femtosecond Kalpha x rays from laser-irradiated plasmas is studied with a view to optimizing photon number and pulse duration. Using analytical numerical models hot electron subsequent transport in range materials, it shown that an optimum laser intensity I(opt) = 7x10(9)Z4.4 exists for maximum yield. Furthermore, demonstrated bulk targets are unsuitable generating sub-ps x-ray pulses: instead, design criteria proposed achieving durations </=100 fs using foils approximately...
The control of light-matter interaction at the quantum level usually requires coherent laser fields. But already an exchange virtual photons with electromagnetic vacuum field alone can lead to coherences, which subsequently suppress spontaneous emission. We demonstrate such spontaneously generated coherences (SGC) in a large ensemble nuclei operating x-ray regime, resonantly coupled common cavity environment. observed SGC originates from two fundamentally different mechanisms related...
Resonant oscillators with stable frequencies and large quality factors help us to keep track of time high precision. Examples range from quartz crystal in wristwatches atomic clocks, which are, at present, our most precise measurement devices1. The search for more convenient reference is continuing2-6. Nuclear are better than because their naturally higher resilience against external perturbations7-9. One the promising cases an ultra-narrow nuclear resonance transition 45Sc between ground...
Abstract Quantum electrodynamics (QED), the quantum field theory that describes interaction between light and matter, is commonly regarded as best-tested in modern physics. However, this claim mostly based on extremely precise studies performed domain of relatively low strengths atoms ions 1–6 . In realm very strong electromagnetic fields such heaviest highly charged (with nuclear charge Z ≫ 1), QED calculations enter a qualitatively different, non-perturbative regime. Yet, corresponding...
We investigate ultrafast (fs) electron dynamics in a liquid hydrogen sample, isochorically and volumetrically heated to moderately coupled plasma state. Thomson scattering measurements using 91.8 eV photons from the free-electron laser Hamburg (FLASH at DESY) show that has been driven nonthermal state with an temperature of 13 ion below 0.1 eV, while density is 2.8x10{20} cm{-3}. For dense plasmas, our experimental data strongly support nonequilibrium kinetics model uses impact ionization...
The polarization purity of 6.457- and 12.914-keV x rays has been improved to the level $2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$ $5.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$. polarizers are channel-cut silicon crystals using six 90\ifmmode^\circ\else\textdegree\fi{} reflections. Their performance possible applications demonstrated in measurement optical activity a sucrose solution.
Group velocity control is demonstrated for x-ray photons of 14.4 keV energy via a direct measurement the temporal delay imposed on spectrally narrow pulses. Subluminal light propagation achieved by inducing steep positive linear dispersion in optical response Fe57 Mössbauer nuclei embedded thin film planar cavity. The detection pulse enabled generating frequency-tunable pulses from broadband pulsed synchrotron radiation. Our theoretical model good agreement with experimental data.Received 29...
The displacive phase transition in SrTiO3 was investigated by means of x-ray diffraction. We used 4.5 keV photons thus probing only a very thin region near the surface. In low temperature lattice parameters evolve substantially different than bulk material. also under influence an epitaxial coating with YBaCu2O7 and found nature changed. near-surface behaves like film.
Laser-plasma particle accelerators could provide more compact sources of high-energy radiation than conventional accelerators. Moreover, because they deliver in femtosecond pulses, improve the time resolution X-ray absorption techniques. Here we show that can measure and control polarization ultra-short, broad-band keV photon pulses emitted from a laser-plasma-based betatron source. The electron trajectories hence X-rays are experimentally controlled by pulse-front tilt driving laser pulses....
The properties of two strongly bent Highly Annealed Pyrolytic Graphite (HAPG) crystals with different thicknesses 40 μm and 100 are studied at all possible reflection orders using x-rays 4.5 keV 8 photon energies. Typical reflecting areas within 50% reflectivity drop boundaries have sizes about ⩽ 1 mm. These domains mis-oriented by minutes arc to each other. mosaicity was measured be ∼ 0.06° on a × mm2 scale, whereas it amounts 0.14° when the probed area becomes > 2 mm2. We find that...
We demonstrate a subpicosecond 1 kHz femtosecond x-ray source with well-accessible quasi-point size (10 microm diameter) providing Cu K(alpha) emission maximum flux of 6.8 x 10(10) photons/s for continuous operation 10 h. A new geometry that essentially facilitates the adjustment and diminishes temporal jitter between probe laser pump pulse is implemented time-resolved diffraction experiments.
Using a high-power femtosecond frequency-doubled Nd:glass laser system with contrast ratio of ${10}^{12}$, the interaction between light and matter up to intensities ${10}^{19}$ W cm${}^{\ensuremath{-}2}$has been investigated. The absorption in solid aluminum is almost independent polarization, peaks at about 25$\ifmmode^\circ\else\textdegree\fi{}$, reaches values 45%. Assuming an exponential electron distribution, temperature 420 keV $4\ifmmode\times\else\texttimes\fi{}{10}^{18}$...
We report the creation of solid-density aluminum plasma using free-electron laser (FEL) radiation at $13.5\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ wavelength. Ultrashort pulses were focused on a bulk Al target, yielding an intensity $2\ifmmode\times\else\texttimes\fi{}{10}^{14}\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$. The emitted from was measured xuv spectrometer. Bremsstrahlung and line ratios yield consistent electron temperatures about...
The properties of high energy density plasma are under increasing scrutiny in recent years due to their importance our understanding stellar interiors, the cores giant planets$^{1}$, and hot inertial confinement fusion devices$^2$. When matter is heated by X-rays, electrons inner shells ionized before valence electrons. Ionization from inside out creates atoms or ions with empty internal electron shells, which known as hollow (or ions)$^{3,4,5}$. Recent advances free-electron laser (FEL)...
We have employed fast electrons produced by intense laser illumination to isochorically heat thermal in solid density carbon temperatures of ∼10,000 K. Using time-resolved x-ray diffraction, the temperature evolution lattice ions is obtained through Debye-Waller effect, and this directly relates electron-ion equilibration rate. This shown be considerably lower than predicted from ideal plasma models. attribute strong ion coupling screening interaction.
Abstract We present a method to determine the bulk temperature of single crystal diamond sample at an X-Ray free electron laser using inelastic X-ray scattering. The experiment was performed high energy density instrument European XFEL GmbH, Germany. technique, based on scattering and principle detailed balance, demonstrated give accurate measurements, within $$8\%$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>8</mml:mn> <mml:mo>%</mml:mo> </mml:mrow>...
An effective x-ray optical method to focus keV pulses shorter than one picosecond by using spherically or toroidally bent crystals is presented. The spectral, spatial, and time-dependent properties of focusing two-dimensional are calculated considering geometrical effects, physical limitation in high performance crystal optics, reflectivities obtained diffraction theory. These compared with first experimental results x rays from a plasma created laser pulse 4.5 mJ energy 100 fs length....