ELI HU Nonprofit Kft.

Szeged, Hungary

ELI HU Nonprofit Kft.

Szeged, Hungary
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Borka D.,Vinča Institute of Nuclear Sciences | Borka Jovanovic V.,Vinča Institute of Nuclear Sciences | Lemell C.,Vienna University of Technology | Tokesi K.,Hungarian Academy of Sciences | Tokesi K.,ELI HU Non profit Kft.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2017

We present simulations for electron transmission through a platinum macrocapillary (diameter d = 3.3. mm, length l = 48. mm) using classical transport theory. Both elastic and inelastic scattering events of primary electrons colliding with the inner wall of the capillary are taken into account. We also model the generation and transport of secondary electrons inside the material. We find excellent agreement of our simulated electron-energy spectra with recent experimental data for 200. eV primary electrons. © 2017 Elsevier B.V.


Nagy G.U.L.,Hungarian Academy of Sciences | Szilasi S.Z.,Hungarian Academy of Sciences | Rajta I.,Hungarian Academy of Sciences | Tokesi K.,Hungarian Academy of Sciences | Tokesi K.,ELI HU Non profit Kft.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2017

We present a classical trajectory Monte Carlo simulation of the transmission of 1MeV H+ microbeam through an insulating macrocapillary. The focused proton beam was launched from the capillary entrance under 1° angle of incidence with respect to the capillary axis. The beam first hit the inner surface of the capillary and the protons were either implanted into the wall of the capillary target or scattered back mostly in forward direction. The formed charge patch on the wall started to deflect the beam due to the Coulomb repulsion. When enough charge accumulated, the deflection angle became large enough to guide the protons through the capillary without close collisions with the surface. During the simulation the charge migration on the capillary surface due to the finite resistivity of the insulator material is taken into account. The time evolution of the transmitted beam was investigated using several incident beam intensities. We found that the efficiency of the guiding depends on the incident beam intensity. In a certain incident intensity range, stable and efficient guiding is observable, which agrees with the experimental observation. © 2017 Elsevier B.V.


Csajbok V.,MTA Lendulet Ultrafast Nanooptics Group | Szikszai L.,MTA Lendulet Ultrafast Nanooptics Group | Nagy B.J.,MTA Lendulet Ultrafast Nanooptics Group | Dombi P.,MTA Lendulet Ultrafast Nanooptics Group | Dombi P.,ELI HU Nonprofit Kft.
Optics Letters | Year: 2016

Improving the laser-induced damage threshold of optical components is a basic endeavor in femtosecond technology. By testing more than 30 different femtosecond mirrors with 42 fs laser pulses at 1 kHz repetition rate, we found that a combination of high-bandgap dielectric materials and improved design and coating techniques enable femtosecond multilayer damage thresholds exceeding 2 J/cm2 in some cases. A significant x2.5 improvement in damage resistance can also be achieved for hybrid Ag-multilayer mirrors exhibiting more than 1 J/cm2 threshold with a clear anticorrelation between damage resistance and peak field strength in the stack. Slight dependence on femtosecond pulse length and substantial decrease for high (megahertz) repetition rates are also observed. © 2016 Optical Society of America.


Racz P.,MTA lendulet Ultrafast Nanooptics Group | Papa Z.,ELI HU Nonprofit Kft. | Papa Z.,University of Szeged | Marton I.,MTA lendulet Ultrafast Nanooptics Group | And 8 more authors.
Nano Letters | Year: 2017

Probing nanooptical near-fields is a major challenge in plasmonics. Here, we demonstrate an experimental method utilizing ultrafast photoemission from plasmonic nanostructures that is capable of probing the maximum nanoplasmonic field enhancement in any metallic surface environment. Directly measured field enhancement values for various samples are in good agreement with detailed finite-difference time-domain simulations. These results establish ultrafast plasmonic photoelectrons as versatile probes for nanoplasmonic near-fields. © 2017 American Chemical Society.


Balogh E.,University of Szeged | Bodi B.,MTA Lendulet Ultrafast Nanooptics Group | Tosa V.,Romanian Institute of Isotopic And Molecular Technology | Goulielmakis E.,Max Planck Institute of Quantum Optics | And 5 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2014

We demonstrate control over attosecond-pulse generation and shaping by numerically optimizing the synthesis of few-cycle to subcycle driver wave forms. The optical wave-form synthesis takes place in an ultrabroad spectral band covering the ultraviolet-infrared domain. These optimized driver waves are used for ultrashort single- and double-attosecond-pulse production (with tunable separation), revealing the potentials of the light wave synthesizer device demonstrated by A. Wirth et al. [Science 334, 195 (2011)SCIEAS0036-807510.1126/science.1210268]. The robustness of the results are also analyzed with respect to attosecond-pulse propagation phenomena. © 2014 American Physical Society.


Varallyay Z.,FETI Ltd. | Varallyay Z.,ELI HU Nonprofit Kft. | Dombi P.,ELI HU Nonprofit Kft. | Dombi P.,MTA Lendulet Ultrafast Nanooptics Group
Applied Optics | Year: 2014

We present a design concept of dielectric gratings containing resonant high (TiO2) and resonant low (SiO2) index dielectric thin-film layers between the grating and the underlying multilayer reflector. We use numerical simulations and the genetic algorithm optimization method to achieve high diffraction efficiency (>97%) in the first diffracted order over a wide wavelength range (∼160 nm) at around 800 nm. The basic concept of the structural optimization contains a high refractive index binary grating with alternating low- and high-index reflector layers, the thicknesses of which are also among the optimization parameters. We introduce two resonant dielectric layers directly below the corrugated TiO2 grating structure and we choose a small (<10%) filling fraction for the grating. This concept allows us to broaden the spectral range where high DE can be achieved. We investigate here gratings for both Littrow-mount and off-Littrow applications. © 2014 Optical Society of America.


Barna I.F.,Hungarian Academy of Sciences | Barna I.F.,ELI HU Nonprofit Kft. | Varro S.,Hungarian Academy of Sciences | Varro S.,ELI HU Nonprofit Kft.
Laser and Particle Beams | Year: 2015

We present a non-relativistic analytic quantum mechanical model to calculate angular differential cross-sections for laser-assisted proton nucleon scattering on a Woods-Saxon optical potential where the nth-order photon absorption is taken into account simultaneously. With this novel description we can integrate two well-established fields, namely low-energy nuclear physics and multi-photon processes together. As a physical example we calculate cross-sections for proton-12C collision at 49 MeV in the laboratory frame in various realistic laser fields. We consider optical Ti:sapphire and X-ray lasers with intensities which are available in existing laser facilities or in the future ELI or X-FEL. Copyright © Cambridge University Press 2015.


Barna I.F.,Hungarian Academy of Sciences | Barna I.F.,ELI HU Nonprofit KFT
Laser Physics | Year: 2014

In our study we consider nonlinear, power-law field-dependent electrical permittivity and magnetic permeability and investigate the time-dependent Maxwell equations with self-similar ansatz. This is a first-order hyperbolic partial differential equation system which can conserve non-continuous initial conditions describing electromagnetic shock. Such phenomena may happen in complex materials induced by the planned powerful Extreme Light Infrastructure laser pulses. © 2014 IOP Publishing Ltd.


Kroo N.,Hungarian Academy of Sciences | Racz P.,Hungarian Academy of Sciences | Varro S.,Hungarian Academy of Sciences | Varro S.,ELI Hu Nonprofit Kft.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2016

Surface plasmons (SPOs) have been excited by intense femtosecond laser pulses on a gold film at room temperature and their near field has been analyzed by the intensity dependent response of an STM and by studying the spectra of multiplasmon emitted electrons. Around 80 GW/cm2 laser intensity, anomalies have been found in both cases, interpreted as the stepping in of electron pairing, transition to a diamagnetic state, and by anomalous Faraday rotation. © 2015 Elsevier B.V. All rights reserved.


Barna I.F.,Hungarian Academy of Sciences | Varro S.,ELI HU Nonprofit Kft.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2016

We present the general theory for proton nuclei scattering in a bichromatic laser field. As a physical example we consider proton collision on 12C at 49 MeV/amu moderate energies in the field of a titan sapphire laser with its second harmonic. © 2015 Elsevier B.V. All rights reserved.

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