A5005604106- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- Terahertz technology and applications
- Ion-surface interactions and analysis
- Diamond and Carbon-based Materials Research
- Photonic and Optical Devices
- Metamaterials and Metasurfaces Applications
- Spectroscopy and Laser Applications
- Photonic Crystals and Applications
- Spectroscopy and Quantum Chemical Studies
- Laser-Matter Interactions and Applications
- Astro and Planetary Science
- Plasmonic and Surface Plasmon Research
- Ionic liquids properties and applications
- Particle accelerators and beam dynamics
- Metallurgical Processes and Thermodynamics
- Magnetic confinement fusion research
- Mechanical and Optical Resonators
- Electrochemical Analysis and Applications
- Gamma-ray bursts and supernovae
- Iron and Steelmaking Processes
- Plant Pathogens and Resistance
- Hemoglobin structure and function
Technical University of Darmstadt
2011-2017
Helmholtz International Center for FAIR
2016
University of Freiburg
2009-2011
Metamaterial layers designed for gigahertz to terahertz (THz)-frequencies have been fabricated by inkjet printing. The spectral response of the structures consisting periodically arranged metallic split-ring resonators is characterized THz-time-domain spectroscopy and compared with identical produced conventional photolithography etching techniques. broader linewidth their resonances shown originate mainly from structural inhomogeneities. Our study shows that printing a viable route...
Using terahertz near-field imaging we experimentally investigate the resonant electromagnetic field distributions behind a split-ring resonator and its complementary structure with sub-wavelength spatial resolution. For out-of-plane components verify complementarity of electric magnetic fields as predicted by Babinet's principle. This duality near-fields can be used to indirectly map close metallic microstructures measuring their analogues which is particularly useful since are still...
Abstract The energy deposition of ions in dense plasmas is a key process inertial confinement fusion that determines the α-particle heating expected to trigger burn wave hydrogen pellet and resulting high thermonuclear gain. However, measurements ion stopping are scarce mostly restricted velocities where theory agrees with data. Here, we report experimental data at low projectile near Bragg peak, force reaches its maximum. This parameter range features largest theoretical uncertainties...
This Letter reports on the measurement of energy loss and projectile charge states argon ions at an 4 MeV/u penetrating a fully ionized carbon plasma. The plasma n(e)≈10(20) cm(-3) T(e)≈180 eV is created by two laser beams λ(Las)=532 nm incident from opposite sides thin foil. resulting spatially homogenous allows us to record precise experimental data. data show increase factor 2 in stopping power which very good agreement with specifically developed Monte Carlo code, that calculation heavy...
The structure and dynamics of ionic liquids (ILs) are unusual due to the strong interactions between ions counter ions. These microscopic properties determine bulk transport critical applications ILs such as advanced fuel cells. terahertz slower relaxations simple alkylammonium nitrate protic (PILs) here studied using femtosecond optical Kerr-effect spectroscopy, dielectric relaxation time-domain spectroscopy. observed give insight into more general liquid behaviour while comparison with...
Imaging and sensing applications based on pulsed terahertz radiation have opened new possibilities for scientific industrial applications. Many exploit the unique features of (THz) spectral region, where common packaging materials are transparent many chemical compounds show characteristic absorptions. Because their diffraction limit, THz far-field imaging techniques lack microscopic resolution and, if subwavelength to be resolved, near-field required. Here, we present a microscopy approach...
We present the first direct experimental test of complex ion structure in liquid carbon at pressures around 100 GPa, using spectrally resolved x-ray scattering from shock-compressed graphite samples. Our results confirm predicted by ab initio quantum simulations and demonstrate importance chemical bonds extreme conditions similar to those found interiors giant planets. The evidence presented here thus provides a firmer ground for modeling evolution current carbon-bearing icy giants like...
We used time-resolved shadowgraphy to characterize the pre-plasma formation in solid-target interaction experiments with micrometer-scale accuracy. performed quantitative measurements of plasma density for amplified spontaneous emission (ASE) levels ranging from 2 · 10(-7) 10(-10) backed 2-dimensional hydrodynamic simulations. find that ASE above 10(-9) are able create a significant plume features canal driving self-focusing laser beam. For 10(-10), no could be detected.
We present experimental data showing an angular separation of laser accelerated proton beams. Using flat plastic targets with thicknesses ranging from 200 nm to 1200 nm, a intensity 6×1020 W cm−2 incident angle 10°, we observe protons in target normal direction cutoff energies around 30 MeV independent the thickness. For best match and conditions, additional signature is detected along axis maximum energy 65 MeV. These different beams can be attributed two acceleration mechanisms acting...
The energy loss of light ions in dense plasmas is investigated with special focus on low to medium projectile energies, i.e., at velocities where the maximum stopping power occurs. In this region, exceptionally large theoretical uncertainties remain and no conclusive experimental data are available. We perform simulations beam-plasma configurations well suited for an test ion highly ionized, laser-generated carbon plasmas. plasma parameters extracted from two-dimensional hydrodynamic...
In this paper we investigate the influence of plasma properties on charge state distribution a swift heavy ion beam interacting with plasma. The main finding is that in can be lower than cold matter. determined by ionization and recombination rates which are balancing each other out. Both, rates, as well atomic excitation decay depend parameters different ways. These effects have been theoretically studied Monte Carlo simulations example an argon at energy...
We present measurements of the complex ion structure warm dense carbon close to melting line at pressures around 100 GPa. High-pressure samples were created by laser-driven shock compression graphite and probed intense laser-generated x-ray sources with photon energies 4.75 keV 4.95 keV. High-efficiency crystal spectrometers allow for spectrally resolving scattered radiation. Comparing ratio elastically inelastically radiation, we find evidence a bonded liquid that is predicted ab-initio...
A technique for the creation of free-standing cryogenic targets laser-driven ion acceleration is presented, which allows us to create solid state consisting initially gaseous materials. In particular, use deuterium and methods its preparation as a target material are discussed. Moving in phase diagram through liquid leads substance covering an aperture on cooled copper frame where it solidified further cooling. An account characterization techniques thickness given, with focus deducing...
An account is given of the Central Laser Facility's work to produce a cryogenic hydrogen targetry system using pulse tube cryocooler. Due increasing demand for low Z thin laser targets, CLF (in collaboration with TUD) have been developing which allows production solid membranes by engineering design can achieve this remotely; enabling gas injection, condensation and solidification without compromising vacuum target chamber. A dynamic sealing mechanism was integrated targets be grown then...
We report on a new experimental setup for ion energy loss measurements in dense moderately coupled plasma which has recently been developed and tested at GSI Darmstadt. A partially ionized, carbon (ne ≤ 0.8• 1022 cm-3, Te = 15 eV, z 2.5, Γ 0.5) is generated by volumetrical heating of two thin foils with soft X-rays. This then probed bunched heavy beam. For that purpose, special double gold hohlraum target sub-millimeter size efficiently converts intense laser light into thermal radiation...
We successfully demonstrated laser-driven ion acceleration with cryogenic hydrogen targets at PHELIX. By using short pulses with200 Ji n500 fs and theuOPA high contrast option [1] an intensity on target of around 5 · 10 20 W/cm 2 was obtained. This enabled the ions from plastic energies up to 65 MeV/nucleon for protons, setting a new record
For ion energy loss measurements in plasmas with near solid densities, an indirect laser heating scheme for carbon foils has been developed at GSI Helmholtzzentrum f\"ur Schwerionenforschung GmbH (Darmstadt, Germany). To achieve electron density of ${10}^{22}\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{3}$ and temperature $10--30\phantom{\rule{0.28em}{0ex}}\mathrm{eV}$, two areal $100\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{g}/{\mathrm{cm}}^{2}$ heated a double-hohlraum...
Simulations have been performed to study the energy loss of carbon ions in a hot, laser-generated plasma velocity region stopping-power maximum. In this parameter range, discrepancies up 30% exist between various stopping theories and hardly any experimental data are available. The considered plasma, created by irradiating thin foil with two high-energy laser beams, is fully-ionized temperature nearly 200 eV. To interaction at maximum power, Monte-Carlo calculations ion charge state carried...