A5051589347- Laser-Matter Interactions and Applications
- Mass Spectrometry Techniques and Applications
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Atomic and Molecular Physics
- Advanced Fiber Laser Technologies
- Photochemistry and Electron Transfer Studies
- Terahertz technology and applications
- Ion-surface interactions and analysis
- Fullerene Chemistry and Applications
- nanoparticles nucleation surface interactions
- Laser-Plasma Interactions and Diagnostics
- Molecular spectroscopy and chirality
- Spectroscopy and Laser Applications
- Photoreceptor and optogenetics research
- Laser-Ablation Synthesis of Nanoparticles
- Porphyrin and Phthalocyanine Chemistry
- Photonic and Optical Devices
- DNA and Nucleic Acid Chemistry
- Foreign Language Teaching Methods
- Plasmonic and Surface Plasmon Research
- Nuclear physics research studies
- Molecular Junctions and Nanostructures
- Nuclear Physics and Applications
- Fluorine in Organic Chemistry
Universität Hamburg
2018-2025
Center for Free-Electron Laser Science
2018-2025
Deutsches Elektronen-Synchrotron DESY
2021-2025
Lund University
2007-2022
Center for Biomolecular Nanotechnologies
2016-2022
Mylan (South Africa)
2017
Mylan (Switzerland)
2017
University of Milan
2017
National Synchrotron Radiation Research Center
2013-2014
Abstract Chiral molecules, used in applications such as enantioselective photocatalysis 1 , circularly polarized light detection 2 and emission 3 molecular switches 4,5 exist two geometrical configurations that are non-superimposable mirror images of each other. These so-called ( R ) S enantiomers exhibit different physical chemical properties when interacting with other chiral entities. Attosecond technology might enable influence over interactions, given it can probe even direct electron...
This review presents the technological infrastructure that will be available at Extreme Light Infrastructure Attosecond Pulse Source (ELI-ALPS) international facility. ELI-ALPS offer to scientific community ultrashort pulses in femtosecond and attosecond domain for time-resolved investigations with unprecedented levels of high quality characteristics. The laser sources beamlines facility make technology accessible scientists lacking access these novel tools. Time-resolved investigation...
Sudden ionisation of a relatively large molecule can initiate correlation-driven process dubbed charge migration, where the electron density distribution is expected to rapidly move along molecular backbone. Capturing this few-femtosecond or attosecond redistribution would represent real-time observation correlation in with enticing prospect following energy flow from single excited other coupled electrons system. Here, we report time-resolved study migration occurring nucleic-acid base...
We demonstrate the generation of few-cycle deep ultraviolet pulses via frequency upconversion 5-fs near-infrared in argon using a laser-fabricated gas cell. The measured spectrum extends from 210 to 340 nm, corresponding transform-limited pulse duration 1.45 fs. extract dispersion-free second-order cross-correlation measurement 1.9 fs, defining new record spectral range.
Abstract We investigate the generation of ultrabroadband femtosecond ultraviolet (UV) radiation via third-order harmonic in highly confined gas media. A dual-stage differential-pumping scheme integrated into a glass microfluidic chip provides an exceptional confinement up to several bar and allows apparatus be operated under high-vacuum environment. UV pulses are generated both argon neon with ∼0.8 μ J energy 0.2% conversion efficiency for spectra that cover UVB UVC regions between 200 325...
Extreme light confinement in plasmonic nanosystems enables novel applications photonics, sensor technology, energy harvesting, biology, and quantum information processing. Fullerenes represent an extreme case for nanoplasmonics: They are subnanometer carbon-based molecules showing high-energy ultrabroad plasmon resonances; however, the fundamental mechanisms driving response corresponding collective electron dynamics still elusive. Here, we uncover dominant role of correlations giant...
The response of metal nanostructures to optical excitation leads localized surface plasmon (LSP) generation with nanoscale field confinement driving applications in, for example, quantum optics and nanophotonics. Field sampling in the terahertz domain has had a tremendous impact on ability trace such collective excitations. Here, we extend capabilities introduce direct LSPs more relevant petahertz domain. method allows measure LSP arbitrary subcycle precision. We demonstrate technique...
We describe a beamline where few-femtosecond ultraviolet (UV) pulses are generated and synchronized to few-cycle near-infrared (NIR) extreme (XUV) attosecond pulses. The UV light is obtained via third-harmonic generation in argon or neon gas when focusing phase-stabilized NIR driving field inside glass cell that was designed support high pressures for enhanced conversion efficiency. A recirculation system allows reducing the large consumption required nonlinear process. Isolated using...
This combined experimental and theoretical study demonstrates that the surface plasmon resonance in ${\mathrm{C}}_{60}$ alters valence photoemission quantum phase, resulting strong effects photoelectron angular distribution emission time delay. Electron momentum imaging spectroscopy is used to measure asymmetry parameter agrees well with our calculations from time-dependent local density approximation (TDLDA). Significant structure delay simultaneously calculated by TDLDA over active...
Tracing secondary rays, such as reflection, refraction and shadow can often be the most costly step in a modern real-time ray tracer. In this paper, we examine problem by using suitable coherence measures present thorough evaluation of different reordering heuristics for rays. We also simple system design more coherent scene traversal caching rays sorted packet-tracing. Although results are only slightly incremental to current research, believe study is an interesting contribution further...
Ultrafast dynamics and fragmentation of thymidine thymine after ionization by attosecond extreme ultraviolet radiation studied in the time-domain.
The fragmentation of the doubly-charged carbon dioxide molecule is studied after photoexcitation to C 1s12πu and O states using a multicoincidence ion-imaging technique. bent component Renner-Teller split populated in 1s→ π* resonant excitation at both oxygen 1s ionization edges opens pathways potential surfaces highly geometries dication. Evidence for complete deformation found coincident detection C+ \documentclass[12pt]{minimal}\begin{document}${\rm O}_2^+$\end{document}O2+ ions. distinct...
The design and performance of a high-resolution momentum-imaging spectrometer for ions which is optimized experiments using synchrotron radiation presented. High collection efficiency achieved by focusing electrostatic lens; long drift tube improves mass resolution position-sensitive detector enables measurement the transverse momentum ions. optimisation lens particle at highest described. We discuss overall present examples demonstrating both kinetics angular measurements in molecular...
The angular anisotropy of fragments created in the dissociation core-electron excited water molecules is studied to probe correlation between fragmentation channels, kinematics and molecular geometry. We present fragment kinetic measurements for where inner-shell oxygen electron unoccupied 4a1 2b2 valence orbitals. individual channels are measured using fully three-dimensional momentum imaging fragments. results show that geometry molecule energy strongly coupled atomisation process. In...
Nuclear motion in the N1s(-1)4a core-excited state of ammonia is investigated by studying angular anisotropy fragments produced decay highly excited molecule and compared with predictions from ab initio calculations. Two different fragmentation channels (H(+)/NH2(+) H(+)/NH(+)/H) reveal complex nuclear dynamics as excitation photon energy tuned through 4a1 resonance. The well-defined dissociation molecular dication species suggests a very rapid time scale limited to low fs timescale.
Dissociative double-photoionization of butadiene in the 25-45 eV energy range has been studied with tunable synchrotron radiation using full three-dimensional ion momentum imaging. Using ab initio calculations, electronic states molecular dication below 33 are identified. The results measurement and calculation show that double ionization from π orbitals selectively triggers twisting about terminal or central C–C bonds. We this conformational rearrangement depends upon state, which...
Dissociative double photoionization of cyclopropane is studied in the inner-valence region using tunable synchrotron radiation. With aid ab initio quantum chemical calculations energies dication states and their favoured fragmentation pathways are determined. These compared to experimental appearance two-body processes kinetic energy released upon dissociation. Photon dependent state-selective dissociation 25-35 eV range found. Calculations suggest that ring-deformation selectively triggered...
While largely studied on the macroscopic scale, dynamics leading to nucleation and fission processes in atmospheric aerosols are still poorly understood at molecular level. Here, we present a joint experimental-theoretical study of model system consisting hydrogen-bonded ammonia water molecules. Experimentally, clusters were produced via adiabatic co-expansion. Double ionization ionic products prepared using synchrotron radiation analyzed with coincidence mass- 3D momentum spectroscopy....
The charge and proton dynamics in hydrogen-bonded networks are investigated using ammonia as a model system. fragmentation of medium-sized clusters (1-2 nm) upon single photon multi-ionization is studied, by analyzing the momenta small ionic fragments. observed pattern doubly- triply-charged reveals spatial anisotropy emission between fragments (back-to-back). Protonated exhibit distinct kinematic correlation, indicating delay ionization (fission). different kinematics for channels...
We report on the versatile design and operation of a two-sided spectrometer for imaging charged-particle momenta in two dimensions (2D) three (3D). The benefits 3D detection are to discern particles different mass study correlations between fragments from multi-ionization processes, while 2D detectors more efficient single-ionization applications. Combining these detector types one instrument allows us detect positive negative simultaneously reduce acquisition times by using at higher...
Experimental studies of core-excited molecules using three-dimensional multi particle momentum imaging are presented where bond rearrangement processes in dication species analysed. The aim the study is to understand relation between geometric changes associated with states and kinetic energy released particular molecular dissociation processes. kinematics individual fragmentation channels studied by fully fragments coincidence. Examples high efficiency instrument capabilities exploited...
Abstract The dynamics of biologically relevant molecules exposed to ionizing radiation contains many facets and spans several orders magnitude in time energy. In the extreme ultraviolet (XUV) spectral range, multi-electronic phenomena bands correlated states with inner-valence holes must be accounted for addition a plethora vibrational modes available dissociation channels. ability track changes charge density bond length during ultrafast reactions is an important endeavor toward more...
A microfluidic chip integrating a gas cell and two lateral differential pumping stages is used to generate ultraviolet supercontinua via third-harmonic generation in neon or argon. Spectra spanning from 200 325 nm are obtained with pulse energies up ~0.8 μJ, corresponding 0.2% conversion efficiency.