Book of Abstracts UltrafastLight Book of Abstracts UltrafastLight-2018

258 Pages·2017·11.75 MB·English

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International Conference on Ultrafast Optical Science (UltrafastLight-2018),
is the broad-scope, annual international symposium dedicated to the most
important aspects of ultrafast phenomena in different fields of natural
sciences and engineering.
The Conference topics:
1. Radiation and nuclear photonics at high fields
2. Ultrafast phenomena in condensed matter and ionized gases
3. Ultrafast laser nanofabrication and nanophotonics
4. Femtosecond non-linear optics. Filamentation.
High field THz generation.
5. Femtosecond laser photobiology and photochemistry.
6. Physics and technology of ultrashort laser pulses and innovative
femtosecond laser technology.
7. Femtosecond radiation in spectroscopy and optical frequency
metrology.
Website: ultrafastlight.lebedev.ru
Chair - Nikolay Kolachevsky (Lebedev Physical Institute of the RAS),
Vice-chair - Andrey Ionin (Lebedev Physical Institute of the RAS)
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Section 1: Radiation and nuclear
photonics at high fields
Section Chair: Andrei Savel’ev (MSU), email: [email protected]
Program committee:
Valeri Bychenkov (LPI, Russia)
Klaus Spohr (ELI-NP, Romania)
Tsuneyuki Ozaki (INRS, Canada)
Bjorn M. Hegelich (The University of Texas at Austin, USA)
Scope
Laser plasma sources of ionizing radiation
Nuclear physics with lasers
Extreme fields physics
Ultra high intensity facilities
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Invited
Efficient generation of attopulses at the interaction of intense
laser radiation with the shaped targets
A. Andreev1,2 and Z. Lecz2
1St. Petersburg State University, Saint Petersburg, Russia;
2Extreme Laser Infrastructure - Attosecond Light Pulse Source (ELI-ALPS), Szeged, Hungary
e-mail: [email protected]
Recently we have proposed an efficient scheme of generation of short dense electron
bunches during the interaction at large angles of incidence of a laser pulse with a limited
foil target [1]. It has been shown that, upon reflection from the target, the relativistic
intensity laser pulse is efficiently converted into a sequence of atto-pulses. Later [2], the
generation of high-intensity atto-pulses has been investigated also in cylindrical geometry
by using 3D PIC code. Due to the rotation-symmetric target, a circularly polarized laser
pulse was considered, propagating on the axis of a hollow cone-like target. The large in-
cidence angle and constant ponderomotive pressure lead to nano-bunching of relativistic
electrons responsible for the laser-driven emission. We found the source and direction
of the coherent radiation that ensures the existence of atto-pulses. The intensity modu-
lation in the harmonic spectrum was well described by the extended model of coherent
synchrotron emission. The spatial distribution of the higher harmonics resembles a spiral
shape which gets focused into a small volume behind the target.
Since the laser pulse reflected from plasma inherently contains low-order harmonics,
a second reflection from a fresh plasma surface leads to the increase of spectral intensity.
In the work [3], we have made an extensive study of multiple reflections of a short pulse
between two solid density plasma walls at oblique incidence, with the help of 2D PIC
simulations. A loosely focused pulse is considered that can propagate between two foils
over consecutive reflections without significant loss of intensity. It is shown that even in
the weakly relativistic regime the intensity of high harmonics can be amplified by three
orders of magnitude with help of this method thus we can increase above considered gen-
erated atto-pulses.
references
[1] A. Andreev, K. Platonov, Optics and Spectroscopy 114, 788 (2013).
[2] Z. Lecz, A. Andreev, Phys Rev E 93, 013207 (2016).
[3] Z. Lech, A. Andreev, Journal of the Optical Society of America B 35, A51 (2018).
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Invited
High energy electrons in relativistic laser-plasma interaction
N.E. Andreev
Joint Institute for High Temperatures of the Russian Academy of Sciences, Moscow, Russia;
Moscow Institute of Physics and Technology, Dolgoprudny, Russia
e-mail: [email protected]
Secondary sources of high energy particles and hard radiation, produced by the action
of short intense laser pulses are widely used for creation and diagnostics of extreme states
ofmatter. Variousmechanismsofheatingandgenerationofhotelectronsintherelativistic
laser interaction with solid and low-density targets are considered. In particular, an
effective generation of highly energetic electrons of tens of MeV energies in near critical
plasma layers is demonstrated. These collimated high energy electron beams carrying the
charge that many orders of magnitude exceed the value predicted by the ponderomotive
Wilks scaling produce short bursts of hard X-rays. Generation of high energy density
states by the ultrahigh contrast femtosecond laser pulses interacting with a near solid
step-like electron density profile is analyzed.
Experimental data on generation of hot electrons and hard radiation obtained at the
facilities of PHELIX (Darmstadt) and JETI40 (Jena) are discussed.
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Student
Optimizing the dephasing length limitation in a laser plasma
accelerator
S. Barzegar
P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia
e-mail: [email protected]
Despite the advanced techniques for improving electron acceleration conditions, the
small amount of dephasing length continues to play a very destructive role in accelerating
electrons. We represent that by injection of different electron profiles and beam loading
effect it is possible to change the ratio of accelerating to decelerating field of the wake-field
using numerical simulations. Therefore, the effective field on the accelerated electrons in
the accelerating phase of the field becomes very small in decelerating phase. Following
this, the electron beam loses a very small amount of energy even when it enters the
decelerating phase. So, the limitation of the dephasing length is greatly reduced.
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Oral
QED cascade with multipetawatt-class lasers: a road
to attosecond-scale highly directed GeV gamma-ray sources
A.V. Bashinov, E.S. Efimenko and A.V. Kim
Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russia
e-mail: [email protected]
We consider the properties of gamma radiation generated during the development
of a quantum electrodynamic cascade in the field of counter-propagating multipetawatt
laser beams configured in the form of a dipole wave. Principal attention is paid to the
linear regime of cascade development, when the emerging plasma almost does not af-
fect the electromagnetic field but can already be a sufficiently effective source of gamma
radiation with unique properties. It is shown that in this regime the considered field
configuration possessing the axial symmetry allows the generation of gamma radiation
with narrow directivity (about 1 mrad for 10 PW level). Moreover, the special features
of particle motion in the fields of tightly focused multipetawatt level laser beams enable
generation of trains or isolated pulses of gamma radiation in the GeV energy range with
attosecond-scale duration. The influence of the cascade on the spectrum of the gener-
ated radiation is revealed and the dependence of the spectrum on the total laser power is
obtained.
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Oral
Stochastic electron heating in combined field of several
overlapping laser pulses of a picosecond duration
S.G. Bochkarev1,5, E. d’Humi`eres2, V.T. Tikhonchuk2,3, Ph. Korneev4
and V.Yu. Bychenkov1,5
1P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia;
2CELIA, University of Bordeaux, CNRS, CEA, Talence, France;
3ELI-Beamlines, Institute of Physics, Czech Academy of Sciences, Doln´ı Bˇreˇzany, Czech
Republic;
4National Research Nuclear University “MEPhI” (Moscow Engineering Physics Institute),
Moscow, Russia;
5Center for Fundamental and Applied Research, VNIIA, ROSATOM, Moscow, Russia
e-mail: [email protected]
Efficient electron acceleration and heating is demonstrated in a multimode structure
created by overlapping of several laser beams of relativistic intensity and picosecond dura-
tion near a sharp target-vacuum interface. The process considered includes a combination
of a slow stochastic heating and a fast regular acceleration in a resonance interaction with
one of the wave packets. It results in formation of a population of energetic electrons
with an exponential distribution in energy characterized by a high effective temperature
and a sharp energy cutoff. Both these parameters depend on the number of crossing
laser beams and the angles of their intersections. This process of laser-electrons inter-
action provides an example of efficient electron heating in vacuum electromagnetic fields
without participation of electrostatic plasma waves. It might contribute to generation
of a suprathermal particle population with an effective temperature significantly exceed-
ing the commonly accepted a standard ponderomotive scaling. This work was partially
supported by RFBR grants (cid:155) 16-02-00088a, 18-02-00452, 17-02-00366a.
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Invited
THz and gamma-ray generation from laser-plasma interaction
A.V. Brantov1, A.C. Kuratov2, M.G. Lobok2, Yu.M. Aliev1, A. Maksimchuk3
and V.Yu. Bychenkov1,2
1P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow, Russia;
2Center of Fundamental and Applied Research (CFAR), VNIIA, ROSATOM, Moscow, Russia;
3Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, USA
e-mail: [email protected]
The sources of secondary electromagnetic radiation based on laser-triggered electrons
have broad potential applications such as medical and biological imaging, diagnostics for
materials science, probing of dense plasmas, security (inspection) systems. Most of these
applications require a brightness of electromagnetic radiation pulse generated during one
shot that has to be enhanced. This can be achieved by choosing a proper (optimized)
scheme of laser-plasma interaction. In this talk we discuss several mechanisms of THz
generation in the interaction of short laser pulses with solid targets. We show how the
strong THz surface wave can be triggered by light pulse at the metal wire surface and how
it propagates along wire in the form of a weakly damped Sommerfeld wave. The electron
bunch guiding along a wire by strong Sommerfeld surface wave field has been modeled.
Such guiding is compared with experimental results.
Based on multidimensional PIC simulations of short laser pulse interaction with ho-
mogeneous planar target, we also present results of an optimization study to find the best
designparameters, whichmaximizethenumberofhigh-energyelectronsgeneratedbysub-
petawatt class laser system for deep gamma radiography purpose. We demonstrate that a
low-density target with electron density of one tenth of critical density irradiated by fem-
tosecondlaserpulsesisoptimalforaccelerationofmaximumnumberofenergeticelectrons
suitable for the MeV bremsstrahlung gamma-ray source for deep gamma-radiography.
This work was supported by RFBR (grants (cid:155) 16-02-00088 and 18-02-00452).
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