A5002708171- Laser-Plasma Interactions and Diagnostics
- Laser-Matter Interactions and Applications
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- Advanced X-ray Imaging Techniques
- Particle Accelerators and Free-Electron Lasers
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Laser Design and Applications
- Crystallography and Radiation Phenomena
- Advanced Fiber Laser Technologies
- Ion-surface interactions and analysis
- Advanced Chemical Physics Studies
- Diamond and Carbon-based Materials Research
- Plasma Diagnostics and Applications
- Quantum, superfluid, helium dynamics
- Advanced Electron Microscopy Techniques and Applications
- Scientific Computing and Data Management
- Geomagnetism and Paleomagnetism Studies
- Mass Spectrometry Techniques and Applications
- Electromagnetic Simulation and Numerical Methods
- Astrophysics and Cosmic Phenomena
- Lightning and Electromagnetic Phenomena
- Solid State Laser Technologies
Technical University of Darmstadt
2022-2025
SLAC National Accelerator Laboratory
2015-2025
Universität Hamburg
2021-2024
Hamburg Institut (Germany)
2024
Center for Free-Electron Laser Science
2023
Helmholtz Institute Jena
2011-2020
Friedrich Schiller University Jena
2012-2020
Lawrence Livermore National Laboratory
2012
The dynamics of energetic particles in strong electromagnetic fields can be heavily influenced by the energy loss arising from emission radiation during acceleration, known as reaction. When interacting with a high-energy electron beam, today's lasers are sufficiently intense to explore transition between classical and quantum reaction regimes. We present evidence collision an ultrarelativistic beam generated laser-wakefield acceleration (ϵ>500 MeV) laser pulse (a0>10). measure postcollision...
Abstract Electron–positron pair plasmas represent a unique state of matter, whereby there exists an intrinsic and complete symmetry between negatively charged (matter) positively (antimatter) particles. These play fundamental role in the dynamics ultra-massive astrophysical objects are believed to be associated with emission ultra-bright gamma-ray bursts. Despite extensive theoretical modelling, our knowledge this matter is still speculative, owing extreme difficulty recreating neutral...
Substantial energy loss in an electron beam passing through a high-intensity laser provides clear evidence of the radiation reaction, shedding light on how electrons interact with extreme electromagnetic fields.
Abstract Diffraction-before-destruction imaging with ultrashort X-ray pulses can visualize non-equilibrium processes, such as chemical reactions, sub-femtosecond precision in the native environment. Here, a nanospecimen diffracts single flash before it disintegrates. The sample structure be reconstructed from coherent diffraction image (CDI). State-of-the-art snapshots lack high spatial resolution because of weak signal. Bleaching effects photo-ionization significantly restrain brightness...
Tracking primary radiation-induced processes in matter requires ultrafast sources and high precision timing. While compact laser-driven ion accelerators are seeding the development of novel instantaneous flux applications, combining ultrashort laser pulse durations with their inherent synchronicity to trace real-time evolution initial damage events has yet be realized. Here we report on absolute measurement proton bursts as short 3.5±0.7 ps from solid target interactions for this purpose....
Controlling the formation and stoichiometric content of desired phases materials has become central interest for a variety fields. The possibility accessing metastable states by initiating reactions X-ray-triggered mechanisms over ultrashort time scales been enabled development X-ray free electron lasers (XFELs). Utilizing exceptionally high-brilliance pulses from EuXFEL, we report synthesis previously unobserved yttrium hydride under high pressure, along with nonstoichiometric changes in...
We revise the calibration of scintillating screens commonly used to detect relativistic electron beams with low average current, e.g., from laser-plasma accelerators, based on new and expanded measurements that include higher charge density different types than previous work [Buck et al., Rev. Sci. Instrum. 81, 033301 (2010)]. Electron peak densities up 10 nC/mm2 were provided by focused picosecond-long delivered Linac for high Brilliance Emittance (ELBE) at Helmholtz-Zentrum...
Experimental results on the acceleration of protons and carbon ions from ultra-thin polymer foils at intensities up to 6 × 1019 W cm−2 are presented revealing quasi-monoenergetic spectral characteristics for different ion species same time. For protons, a linear correlation between cutoff energy peak is observed when laser intensity increased. Particle-in-cell simulations supporting experimental imply an mechanism driven by radiation pressure as predicted multi-component these intensities.
High order harmonics generated at relativistic intensities have long been recognized as a route to the most powerful extreme ultraviolet pulses. Reliably generating isolated attosecond pulses requires gating only single dominant optical cycle, but techniques developed for lower power lasers not readily transferable. We present novel method temporally gate pulse trains by combining noncollinear and polarization gating. This scheme uses split beam configuration which allows be implemented high...
We present a design for pixelated scintillator based gamma-ray spectrometer non-linear inverse Compton scattering experiments. By colliding laser wakefield accelerated electron beam with tightly focused, intense pulse, photons up to 100 MeV energies and few femtosecond duration may be produced. To measure the energy spectrum angular distribution, 33 × 47 array of cesium-iodide crystals was oriented such that crystal length axis parallel in vertical direction. Using an iterative deconvolution...
Plasma wakefield accelerators can be driven either by intense laser pulses (LWFA) or particle beams (PWFA). A third approach that combines the complementary advantages of both types plasma accelerator has been established with increasing success over last decade and is called hybrid LWFA→PWFA. Essentially, a compact LWFA exploited to produce an energetic, high-current electron beam as driver for subsequent PWFA stage, which, in turn, phase-constant, inherently laser-synchronized,...
Measuring signatures of strong-field quantum electrodynamics (SF-QED) processes in an intense laser field is experimental challenge: it requires detectors to be highly sensitive single electrons and positrons the presence typically very strong x-ray $\gamma$-photon background levels. In this paper, we describe a particle detector capable diagnosing leptons from SF-QED interactions discuss level simulations for upcoming Experiment-320 at FACET-II (SLAC National Accelerator Laboratory). The...
We report on the first demonstration of passive all-optical plasma lensing using a two-stage setup. An intense femtosecond laser accelerates electrons in wakefield accelerator (LWFA) to 100 MeV over millimeter length scales. By adding second gas target behind initial LWFA stage we introduce robust and independently tunable lens. observe density dependent reduction electron beam divergence from an value 2.3 mrad, down 1.4 mrad (rms), when lens is operation. Such provides simple compact...
Controlling the parameters of a laser plasma accelerated electron beam is topic intense research with particular focus placed on controlling injection phase electrons into accelerating structure from background plasma. An essential prerequisite for high-quality beams dark-current free acceleration (i.e., no beyond those deliberately injected). We show that small-scale density ripples in are sufficient to cause uncontrolled (self-)injection electrons. Such can be as short ∼50 μm and therefore...
The structures, strain fields, and defect distributions in solid materials underlie the mechanical physical properties across numerous applications. Many modern microstructural microscopy tools characterize crystal grains, domains defects required to map lattice distortions or deformation, but are limited studies of (near) surface. Generally speaking, such cannot probe structural dynamics a way that is representative bulk behavior. Synchrotron X-ray diffraction based imaging has long mapped...
Experimental results on relativistic surface HHG at a repetition rate of 10 Hz are presented. Average powers in the μW range generated spectral 51 to 26 nm (24–48 eV). The harmonic radiation is produced by focusing second-harmonic high-power laser onto rotating glass moderately intensities 3 × 1019 W cm−2. emission exhibits divergence mrad. Together with absolute photon numbers recorded calibrated spectrometer, this allows for determination extreme ultraviolet (XUV) yield. pulse energies...
We report on the absolute sensitivity calibration of an extreme ultraviolet (XUV) spectrometer system that is frequently employed to study emission from short-pulse laser experiments. The XUV spectrometer, consisting a toroidal mirror and transmission grating, was characterized at synchrotron source in respect ratio detected incident photon flux energies ranging 15.5 eV 99 eV. allows determination number emitted by laser-based sources, e.g., high-harmonic generation plasma surfaces or...
The generation of high-quality relativistic positron beams is a central area research in experimental physics, due to their potential relevance wide range scientific and engineering areas, ranging from fundamental science practical applications. There now growing interest developing hybrid machines that will combine plasma-based acceleration techniques with more conventional radio-frequency accelerators, order minimise the size cost these machines. Here we report on recent experiments...
We present experimental evidence of relativistic electron-cyclotron resonances (RECRs) in the vicinity relativistically intense pump laser a wakefield accelerator (LWFA). The effects RECRs are visualized by imaging driven plasma wave with few-cycle, optical probe transverse geometry. experiences strong, spectrally dependent and modified birefringence that arises due to electrons' motion pump's electromagnetic fields. spectral is strongly on local magnetic field distribution laser. Analysis...
We report on the performance of a system employing multi-layer coated mirror creating circularly polarized light in fully reflective setup. With one specially designed we are able to create laser pulses with an ellipticity more than ε = 98% over entire spectral bandwidth from initially linearly Titanium:Sapphire femtosecond pulses. tested homogeneity polarization beam sizes order approximately 10 cm. The damage threshold was determined be nearly 400 times higher for transmissive quartz-wave...
Free Electron Lasers (FEL) are commonly regarded as the potential key application of laser wakefield accelerators (LWFA). It has been found that electron bunches exiting from state-of-the-art LWFAs exhibit a normalized 6-dimensional beam brightness comparable to those in conventional linear accelerators. Effectively exploiting this beneficial property for LWFA-based FELs is challenging due extreme initial conditions particularly terms divergence and energy spread. Several different...