Dr
Pavel Evtushenko
(HZDR / ELBE)
02/05/2019, 09:30
FELs / Accelerators
The Radiation Source ELBE at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is a user facility based on a 1 mA - 40 MeV CW SRF LINAC. Presently HZDR is considering upgrade options for the ELBE or its replacement with a new CW, SRF LINAC-based user facility. A part of the user requirements is the capability to generate IR and THz pulse in the frequency range from 0.1 through 30 THz, with pulse...
Prof.
Alec Wodtke
(Max Planck Institute for biophysical chemistry)
02/05/2019, 10:00
Knowledge of the rates of elementary gas phase reactions has contributed decisively to our understanding of important chemistry with great human impact. For example rate-constant data bases for atmospheric chemistry provide the essential input for computer models of urban air pollution, stratospheric ozone depletion and global climate change. Developing databases for elementary chemical...
Dr
Barratt Park
(Max Planck Institute for Biophysical Chemistry)
02/05/2019, 10:30
VUV FEL applications
Invited Oral
Electron transfer at surfaces is central to catalysis and electrochemistry. Such processes often involve nonadiabatic dynamics, which present extreme challenges for ab initio theory. Experiments have demonstrated the importance of electronically nonadiabatic dynamics in the trapping of H-atoms at metal surfaces, where the mechanism is dominated by nonadiabatic loss of translational energy to...
Prof.
Eckart Rühl
(Physikalische Chemie, Freie Universität Berlin)
02/05/2019, 11:30
Invited Oral
Free nanoparticles are of primary interest for investigating in intense radiation fields the surface and bulk properties of well-defined nanoscopic matter including size effects without experiencing electrical charging and radiation damage. Photon-induced dynamics of free nanoparticles is briefly reviewed. The dynamics of photoemission, ion emission, and light scattering is reported, which...
Dr
Rebecca Ingle
(École Polytechnique Fédérale de Lausanne)
02/05/2019, 12:00
VUV FEL applications
Invited Oral
Time-resolved photoelectron spectroscopy (TR-PES) is a powerful tool for examining the photoinduced dynamics of molecules in the gas or solution phase.[1] However, to fully exploit the power of TR-PES for unravelling complex photochemical reactions, it is necessary to have probe photons of sufficiently high energy, capable of ionising the system of interest over the full range of the potential...
Dr
Tim Laarmann
(HASYLAB/DESY)
02/05/2019, 12:30
VUV FEL applications
Electron wave packet interferometry provides the full motion picture of non-stationary states, their relative amplitudes and phases and dominant relaxation pathways. The demonstrated sensitivity to phase changes on the few-attosecond time scale makes this method a powerful tool to probe even weak electronic perturbations and couplings, respectively. In this contribution I will present first...
Prof.
Roland Wester
(Universität Innsbruck)
02/05/2019, 14:00
Invited Oral
In this presentation, I will discuss photodetachment and photodissociation experiments of cold trapped ions. Results in the form of photodestruction cross sections are particularly relevant for modeling ion abundances in interstellar molecular clouds.
Prof.
Elaine Seddon
(Daresbury Lab, University of Manchester, UK)
02/05/2019, 14:30
Prof.
Oliver Rader
(Helmholtz-Zentrum Berlin)
02/05/2019, 15:00
Invited Oral
The electron spin plays an important role in topological matter because the lifting of the spin degeneracy by the spin-orbit interaction is crucial. Moreover, the interaction of topological insulators with ferromagnets enables novel effects such as the quantum anomalous Hall effect. Spin- and angle-resolved photoemission is an efficient probe of the spin-dependent occupied electronic...
Prof.
Helmut Zacharias
(University of Münster)
03/05/2019, 09:00
VUV FEL applications
Invited Oral
The interaction XUV and VUV radiation with doped molecular ices on grains is important for light-assisted association or dissociation reactions in or on these ices, particularly in accretion disks and the photon dominated regions of interstellar clouds [1]. Important insights into the non-thermal desorption kinetics of CO from pure CO [2] and CO:N2 ice mixtures [3] have been obtained through...
Dr
Maksim Grechko
(Max Planck Institute for Polymer Research)
03/05/2019, 09:30
Invited Oral
Water and ice surfaces and interfaces are ubiquitous, not just in nature (e.g. for various naturally occurring forms of snow and ice) but also in many technological applications (such as food science and artificial snow machines). Water is a rather unique liquid, owing to its strong intermolecular interactions: strong hydrogen bonds hold water molecules together. At the surface of ice, the...
Dr
Michele Puppin
(École Polytechnique Fédérale de Lausanne)
03/05/2019, 10:00
Invited Oral
Time-resolved photoemission, combined with angle-resolved acquisition, can extend band-structure mapping to excited states which are only occupied out-of-equilibrium and evolve on a femtosecond timescale [1]. The full potential of time- and angle-resolved photoemission spectroscopy (trARPES) is reached by performing the experiment with time-bandwidth-limited pulses at high repetition rates -...
Dr
David Osborn
(Sandia National Laboratories)
03/05/2019, 11:00
VUV FEL applications
Invited Oral
We have developed a technique called Multiplexed Photoionization Mass Spectrometry for the study of unimolecular and bimolecular chemical reactions. We utilize a low repetition rate pulsed UV laser to initiate a chemical reaction in a collisional environment by breaking a bond in a precursor molecule. The resulting free radicals (resulting from unimolecular dissociation), and the ensuing...
Dr
Isabella Gierz
(MPI-SD Hamburg and University of Regensburg)
03/05/2019, 11:30
VUV FEL applications
Invited Oral
The structure and electronic properties of a solid are determined by the deepest minimum on its potential energy surface. To date there are different well established means to shape the potential energy surfaces and thereby control the electronic properties such as varying the chemical composition of a material, changing the temperature, or applying strong magnetic fields. The development of...
Dr
Simone Di Mitri
(FERMI@Eletta)
03/05/2019, 12:00
FELs / Accelerators
Invited Oral
The talk describes electron and photon beam manipulation techniques for control of the bandwidth and temporal duration of FERMI VUV FEL pulses. An overview of the FEL performance in relation to specific user needs is given.
Dr
Arkady Krasheninnikov
(Helmholtz-Zentrum Dresden-Rossendorf)
03/05/2019, 12:30
Invited Oral
Ion irradiation has successfully been used for introducing impurities and creating defects in two-dimensional (2D) materials in a controllable manner. Moreover, focused ion beams, especially when combined with in-situ or post-irradiation chemical treatments, can be employed for patterning and even cutting 2D systems with a high spatial resolution. The optimization of this process requires the...
Dr
Jan-Christoph Deinert
(Helmholtz-Zentrum Dresden-Rossendorf)
03/05/2019, 14:00
VUV FEL applications
Invited Oral
Low-energy Terahertz (THz) excitation at surfaces offers resonant access to a multitude of fundamental modes, e.g., lattice vibrations, molecular rotations, spin precession and the motion of free electrons [1]. The TELBE THz facility at HZDR aims at controlling and manipulating these degrees of freedom in the nonlinear regime and thereby resolving the resulting dynamics on a femtosecond...
Dr
Ralph Ernstorfer
(Fritz-Haber-Institut)
03/05/2019, 14:15
in collaboration with:
S. Dong, P. Xian, S. Beaulieu, M. Dendzik, T. Pincelli, M. Puppin, C. Nicholson, Y. Windsor, M. Wolf, L. Rettig
Recent developments of photoelectron spectrometers based on time-of-flight techniques using multi-dimensional delay-line detectors such as k-TOFs and momentum microscopes are fueling the emerging field of multidimensional photoemission spectroscopy (MPES)...
Prof.
Ulrich Höfer
(Philipps-University of Marburg, Marburg, Germany)
03/05/2019, 14:45
Invited Oral
There is an increasing interest to control and manipulate the properties of solids with intense light fields. Prominent examples are photo-induced insulator-to-metal transitions, light-induced superconductivity, the observation of Floquet-Bloch states and light-wave driven electrical currents. Experiments along these lines benefit tremendously when the capability of angle-resolved...