A5046473285- Laser-Plasma Interactions and Diagnostics
- Laser-Matter Interactions and Applications
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Advanced Fiber Laser Technologies
- Laser Design and Applications
- Particle Accelerators and Free-Electron Lasers
- Advanced X-ray Imaging Techniques
- Solid State Laser Technologies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Pulsed Power Technology Applications
- Gyrotron and Vacuum Electronics Research
- Terahertz technology and applications
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Planetary Science and Exploration
- Mass Spectrometry Techniques and Applications
- Laser Material Processing Techniques
- Atomic and Subatomic Physics Research
- Advanced Optical Sensing Technologies
- Advanced Surface Polishing Techniques
- Spam and Phishing Detection
- Ocular and Laser Science Research
Max Planck Institute of Quantum Optics
2015-2024
Ludwig-Maximilians-Universität München
2015-2024
Max Planck Institute for Psycholinguistics
2024
Open University of the Netherlands
2020-2023
TH Köln - University of Applied Sciences
2013-2023
Radboud University Nijmegen
2023
Centre for Advanced Laser Applications
2021
Max Planck Society
2004-2014
University of Cologne
2010-2013
Heinrich Heine University Düsseldorf
2010
The laminarity of high-current multi-MeV proton beams produced by irradiating thin metallic foils with ultraintense lasers has been measured. For energies >10 MeV, the transverse and longitudinal emittance are, respectively, <0.004 mm mrad <10(-4) eV s, i.e., at least 100-fold may be as much 10(4)-fold better than conventional accelerator beams. fast acceleration being electrostatic from an initially cold surface, only collisions accelerating electrons appear to limit beam laminarity. ion...
Collimated jets of carbon and fluorine ions up to 5 MeV/nucleon ( approximately 100 MeV) are observed from the rear surface thin foils irradiated with laser intensities x 10 (19)W/cm(2). The normally dominant proton acceleration could be surpressed by removing hydrocarbon contaminants resistive heating. This inhibits screening effects permits effective energy transfer other ion species. dynamics spatiotemporal distributions accelerating E fields at target inferred detailed spectra.
Recent theoretical calculations predicted an order-of-magnitude increase in the efficiency of terahertz pulse generation by optical rectification lithium niobate when 500 fs long pump pulses are used, rather than commonly used ~100 pulses. Even using longer optimal 1.3 ps duration, 2.5× higher THz energy (125 μJ) was measured with pump-to-THz conversion (0.25%) reported previously shorter These results verify advantage and support expectation that mJ-level will be available cooling crystal...
We report the generation of stable and tunable electron bunches with very low absolute energy spread ($\ensuremath{\Delta}E\ensuremath{\approx}5\text{ }\text{ }\mathrm{MeV}$) accelerated in laser wakefields via injection trapping at a sharp downward density jump produced by shock front supersonic gas flow. The peak highly reproducible spectrum was tuned over more than 1 order magnitude, containing charge 1--100 pC per interval $10\text{ }\mathrm{pC}/\mathrm{MeV}$. Laser-plasma acceleration...
Efficient generation of THz pulses with high energy was demonstrated by optical rectification 785-fs laser in lithium niobate using tilted-pulse-front pumping. The enhancement conversion efficiency a factor 2.4 to 2.7 up 186 μJ cryogenic cooling the generating crystal and 18.5 mJ/cm2 pump fluence. Generation more than 0.4 mJ 0.77% even at room temperature increasing fluence mJ/cm2. spectral peak is about 0.2 THz, suitable for charged-particle manipulation.
Al x Ga 1−x N alloys were grown on c-plane sapphire by plasma-induced molecular beam epitaxy. The content was varied over the whole composition range (0⩽x⩽1). molar fraction deduced from x-ray diffraction and for comparison elastic recoil detection analysis. of calculated lattice parameter c underestimates x. This is due to a deformation unit cell. exact mole biaxial strain can be an additional determination a, using asymmetric reflections. results obtained provide evidence validity Vegard’s...
We present the results of a detailed study on acceleration intense ion beams by relativistic laser plasmas. The experiments were performed at 100 TW Laboratoire pour L'Utilisation des Lasers Intenses. investigated dependence target conditions based theoretical predictions normal sheath mechanism. A strong beam parameters rear surface was found. succeeded in shaping appropriate tailoring geometry and we characterization quality. production heavy could be achieved suppressing amount protons...
Laser-driven, quasimonoenergetic electron beams of up to approximately 200 MeV in energy have been observed from steady-state-flow gas cells. These emitted within a low-divergence cone 2.1+/-0.5 mrad FWHM display unprecedented shot-to-shot stability (2.5% rms), pointing (1.4 and charge (16% rms) owing highly reproducible gas-density profile the interaction volume. Laser-wakefield acceleration cells this type provides simple reliable source relativistic electrons suitable for applications...
A beam of multi-MeV helium ions has been observed from the interaction a short-pulse high-intensity laser pulse with underdense plasma. The ion was found to have maximum energy for He2+ (40(+3)(-8)) MeV and directional along propagation path, highest being collimated cone less than 10 degrees. 2D particle-in-cell simulations show that are accelerated by sheath electric field is produced at back gas target. This generated transfer hot electron beam, which exits target generating large...
We present an all-laser-driven, energy-tunable, and quasimonochromatic x-ray source based on Thomson scattering from laser-wakefield-accelerated electrons. One part of the laser beam was used to drive a few-fs bunch quasimonoenergetic electrons, while remainder backscattered off at weakly relativistic intensity. When electron energy tuned 17--50 MeV, narrow spectra peaking 5--42 keV were recorded with high resolution, revealing nonlinear features. large set measurements showing stability...
Using quadrupole scan measurements we show laser-wakefield accelerated electrons to have a normalized transverse emittance of ${0.21}_{\ensuremath{-}0.02}^{+0.01}\ensuremath{\pi}\text{ }\mathrm{mm}\text{ }\mathrm{mrad}$ at 245 MeV. We demonstrate multishot and single-shot method, the mean values for both methods agree well. A simple model beam dynamics in plasma density downramp accelerator exit matches source size divergence inferred from measurement. In energy range 300 MeV remains constant.
X-ray phase-contrast imaging has recently led to a revolution in resolving power and tissue contrast biomedical imaging, microscopy materials science. The necessary high spatial coherence is currently provided by either large-scale synchrotron facilities with limited beamtime access or microfocus tubes rather flux. X-rays radiated relativistic electrons driven well-controlled high-power lasers offer promising route proliferation of this powerful technology. A laser-driven plasma wave...
The first-order helical Laguerre–Gaussian mode (also called donut mode) is used to improve the energy throughput of nonlinear spectral broadening in gas-filled multipass cells. method proposed this Letter enables, for first time best our knowledge, pulses with energies beyond 100 mJ and suitable an average power more than 500 W while conserving excellent spatio-spectral homogeneity <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD">...
The evolution of laser-generated MeV, MA electron beams propagating through conductors and insulators has been studied by comparing measurement modeling the distribution MeV protons that are sheath accelerated propagated electrons. We find flow metals is uniform can be laser imprinted, whereas propagation induces spatial disruption fast Agreement found with material dependent modeling.
We report experimental results on laser-driven electron acceleration with low divergence. The beam was generated by focussing 750 mJ, 42 fs laser pulses into a gas-filled capillary discharge waveguide at densities in the range between 10 18 and 19 cm 3 . Quasi-monoenergetic bunches energies as high 500 MeV have been detected, features reaching up to 1 GeV, albeit large shot-to-shot fluctuations. A more stable regime higher bunch charge (20-45 pC) less energy (200-300 MeV) could also be...
The comparative efficiency and beam characteristics of high-energy ions generated by high-intensity short-pulse lasers (approximately 1-6 x 10(19) W/cm2) from both the front rear surfaces thin metal foils have been measured under identical conditions. Using direct measurements nuclear activation techniques, we find that rear-surface acceleration produces higher energy particles with smaller divergence a than front-surface acceleration. Our observations are well reproduced realistic...
Highly collimated, quasimonoenergetic multi-MeV electron bunches were generated by the interaction of tightly focused, 80-fs laser pulses in a high-pressure gas jet. These monoenergetic are characteristic wakefield acceleration highly nonlinear wave breaking regime, which was previously thought to be accessible only much shorter thinner plasmas. In our experiment, initially long pulse modified underdense plasma match necessary conditions. This picture is confirmed semianalytical scaling laws...
We present what we believe to be the first terawatt diode-pumped laser employing single-crystalline Yb:CaF(2) as amplifying medium. A maximum pulse energy of 420 mJ at a repetition rate 1 Hz was achieved by seeding with stretched femtosecond 2 ns in duration, preamplified 40 mJ. After recompression, 197 and duration 192 fs were obtained, corresponding peak power TW. Furthermore, nanosecond pulses containing an up 905 generated without optical damage.
We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering an all-optical way within 8 mrad opening window with respect initial laser axis. also discovered evidence collective electron-betatron oscillations due off-axis electron injection into wakefield induced by pulse-front tilt....
Ion beams are relevant for radiobiological studies and tumor therapy. In contrast to conventional accelerators, laser-driven ion acceleration offers a potentially more compact cost-effective means of delivering ions radiotherapy. Here, we show that by combining advanced using nanometer thin targets beam transport, truly nanosecond quasi-monoenergetic proton bunches can be generated with table-top laser system, single shot doses up 7 Gy living cells. Although in their infancy, laser-ion...
We report on new charge calibrations and linearity tests with high-dynamic range for eight different scintillating screens typically used the detection of relativistic electrons from laser-plasma based acceleration schemes. The absolute calibration was done picosecond electron bunches at ELBE linear accelerator in Dresden. lower limit our setup most sensitive screen (KODAK Biomax MS) 10 fC/mm(2). showed a photon-to-charge dependency over several orders magnitude. An onset saturation effects...