arXiv subjects

T. V. Liseykina

Publications and source records attributed to T. V. Liseykina.

13 recordsLinked to original sources

arXiv2020

Quantum effects on radiation friction driven magnetic field generation

Radiation losses in the interaction of superintense circularly polarized laser pulses with high-density plasmas can lead to the generation of strong quasistatic magnetic fields via absorption of the photon angular momentum (so called inverse Faraday effect). To achieve the magnetic field strength of several Giga Gauss laser intensities $\simeq 10^{24}$W/cm$^2$ are required which brings the interaction to the border between the classical and the quantum regimes. We improve the classical modeling of the laser interaction with overcritical plasma in the "hole boring" regime by using a modified radiation friction force accounting for quantum recoil and spectral cut-off at high energies. The results of analytical calculations and three-dimensional particle-in-cell simulations show that, in foreseeable scenarios, the quantum effects may lead to a decrease of the conversion rate of laser radiation into high-energy photons by a factor 2-3. The magnetic field amplitude is suppressed accordingly, and the magnetic field energy - by more than one order in magnitude. This quantum suppression is shown to reach a maximum at a certain value of intensity, and does not grow with the further increase of intensities. The non monotonic behavior of the quantum suppression factor results from the joint effect of the longitudinal plasma acceleration and the radiation reaction force. The predicted features could serve as a suitable diagnostic for radiation friction theories.

physics.plasm-ph↗

arXiv2019

Bright single-cycle terahertz source based on gas cells irradiated by two-color laser pulses

We study the excitation of electron currents in a transparent cell of sub-millimeter size filled by an atomic gas and illuminated by an intense two-color femtosecond laser pulse. The pulse consists of a strong fundamental component and its second harmonic of low intensity, both circularly polarized. We show that for sufficiently small $20μ$m cells the plasma oscillation excited by asymmetric ionization is almost spatially homogeneous within the interaction volume. This coherent dipole plasma oscillation results in a remarkably efficient conversion of the electron energy into that of radiation emitted in the terahertz frequency domain. Simultaneously, strong quasi-static electric fields of maximal strength $E_m\simeq 10$MV/cm are shown to exist inside the cell during several hundred femtoseconds after the ionizing two-color laser pulse has gone.

physics.atom-ph↗

arXiv2019

Efficiency of radiation friction losses in laser-driven "hole boring" of dense targets

In the interaction of laser pulses of extreme intensity ($>10^{23}~{\rm W cm}^{-2}$) with high-density, thick plasma targets, simulations show significant radiation friction losses, in contrast to thin targets for which such losses are negligible. We present an analytical calculation, based on classical radiation friction modeling, of the conversion efficiency of the laser energy into incoherent radiation in the case when a circularly polarized pulse interacts with a thick plasma slab of overcritical initial density. By accounting for three effects including the influence of radiation losses on the single electron trajectory, the global `hole boring' motion of the laser-plasma interaction region under the action of radiation pressure, and the inhomogeneity of the laser field in both longitudinal and transverse direction, we find a good agreement with the results of three-dimensional particle-in-cell simulations. Overall, the collective effects greatly reduce radiation losses with respect to electrons driven by the same laser pulse in vacuum, which also shift the reliability of classical calculations up to higher intensities.

physics.plasm-ph↗

arXiv2016

Inverse Faraday Effect driven by Radiation Friction

A collective, macroscopic signature to detect radiation friction in laser-plasma experiments is proposed. In the interaction of superintense circularly polarized laser pulses with high density targets, the effective dissipation due to radiative losses allows the absorption of electromagnetic angular momentum, which in turn leads to the generation of a quasistatic axial magnetic field. This peculiar "inverse Faraday effect" is investigated by analytical modeling and three-dimensional simulations, showing that multi-gigagauss magnetic fields may be generated at laser intensities $>10^{23}~\mbox{W cm}^{-2}$.

physics.plasm-ph↗

arXiv2015

Ion-acoustic Shocks with Self-Regulated Ion Reflection and Acceleration

An analytic solution describing an ion-acoustic collisionless shock, self-consistently with the evolution of shock-reflected ions, is obtained. The solution extends the classic soliton solution beyond a critical Mach number, where the soliton ceases to exist because of the upstream ion reflection. The reflection transforms the soliton into a shock with a trailing wave and a foot populated by the reflected ions. The solution relates parameters of the entire shock structure, such as the maximum and minimum of the potential in the trailing wave, the height of the foot, as well as the shock Mach number, to the number of reflected ions. This relation is resolvable for any given distribution of the upstream ions. In this paper, we have resolved it for a simple "box" distribution. Two separate models of electron interaction with the shock are considered. The first model corresponds to the standard Boltzmannian electron distribution in which case the critical shock Mach number only insignificantly increases from M=1.6 (no ion reflection) to M=1.8 (substantial reflection). The second model corresponds to adiabatically trapped electrons. They produce a stronger increase, from M=3.1 to M=4.5. The shock foot that is supported by the reflected ions also accelerates them somewhat further. A self-similar foot expansion into the upstream medium is also described analytically.

physics.plasm-ph↗

arXiv2014

Plasma-Based Generation and Control of a Single Few-Cycle High-Energy Ultrahigh-Intensity Laser Pulse

A laser-boosted relativistic solid-density paraboloidal foil is known to efficiently reflect and focus a counterpropagating laser pulse. Here we show that in the case of an ultrarelativistic counterpropagating pulse, a high-energy and ultrahigh intensity reflected pulse can be more effectively generated by a relatively slow and heavy foil than by a fast and light one. This counterintuitive result is explained with the larger reflectivity of a heavy foil, which compensates for its lower relativistic Doppler factor. Moreover, since the counterpropagating pulse is ultrarelativistic, the foil is abruptly dispersed and only the first few cycles of the counterpropagating pulse are reflected. Our multi-dimensional particle-in-cell simulations show that even few-cycle counterpropagating laser pulses can be further shortened (both temporally and in the number of laser cycles) with pulse amplification. A single few-cycle, multi-petawatt laser pulse with several joule of energy and with peak intensity exceeding 10^23 W/cm^2 can be generated already employing next-generation high-power laser systems. In addition, the carrier-envelope phase of the generated few-cycle pulse can be tuned provided that the carrier-envelope phase of the initial counterpropagating pulse is controlled.

physics.plasm-ph↗

arXiv2013

Plasma Formation Dynamics in Intense Laser-Droplet Interaction

We study the ionization dynamics in intense laser-droplet interaction using three-dimensional, relativistic particle-in-cell simulations. Of particular interest is the laser intensity and frequency regime for which initially transparent, wavelength-sized targets are not homogeneously ionized. Instead, the charge distribution changes both in space and in time on a sub-cycle scale. One may call this the extreme nonlinear Mie-optics regime. We find that - despite the fact that the plasma created at the droplet surface is overdense - oscillating electric fields may penetrate into the droplet under a certain angle, ionize, and propagate in the just generated plasma. This effect can be attributed to the local field enhancements at the droplet surface predicted by standard Mie theory. The penetration of the fields into the droplet leads to the formation of a highly inhomogeneous charge density distribution in the droplet interior, concentrated mostly in the polarization plane. We present a self-similar, exponential fit of the fractional ionization degree which depends only on a dimensionless combination of electric field amplitude, droplet radius, and plasma frequency with only a weak dependence on the laser frequency in the overdense regime.

physics.plasm-ph↗

arXiv2012

Dynamics of self-generated, large amplitude magnetic fields following high-intensity laser matter interaction

The dynamics of magnetic fields with amplitude of several tens of Megagauss, generated at both sides of a solid target irradiated with a high intensity (? 1019W/cm2) picosecond laser pulse, has been spatially and temporally resolved using a proton imaging technique. The amplitude of the magnetic fields is sufficiently large to have a constraining effect on the radial expansion of the plasma sheath at the target surfaces. These results, supported by numerical simulations and simple analytical modeling, may have implications for ion acceleration driven by the plasma sheath at the rear side of the target as well as for the laboratory study of self-collimated high-energy plasma jets.

physics.plasm-ph↗

arXiv2011

Radiation pressure dominant acceleration: polarization and radiation reaction effects, and energy increase in three-dimensional simulations

Polarization and radiation reaction (RR) effects in the interaction of a superintense laser pulse (I > 10^23 W/cm^2) with a thin plasma foil are investigated with three dimensional particle-in-cell (PIC) simulations. For a linearly polarized laser pulse, strong anisotropies such as the formation of two high-energy clumps in the plane perpendicular to the propagation direction and significant radiation reactions effects are observed. On the contrary, neither anisotropies nor significant radiation reaction effects are observed using circularly polarized laser pulses, for which the maximum ion energy exceeds the value obtained in simulations of lower dimensionality. The dynamical bending of the initially flat plasma foil leads to the self-formation of a quasi-parabolic shell that focuses the impinging laser pulse strongly increasing its energy and momentum densities.

physics.plasm-ph↗

arXiv2009

Relativistic Attosecond Electron Bunches from Laser-Illuminated Droplets

The generation of relativistic attosecond electron bunches is observed in three-dimensional, relativistic particle-in-cell simulations of the interaction of intense laser light with droplets. The electron bunches are emitted under certain angles which depend on the ratios of droplet radius to wavelength and plasma frequency to laser frequency. The mechanism behind the multi-MeV attosecond electron bunch generation is investigated using Mie theory. It is shown that the angular distribution and the high electron energies are due to a parameter-sensitive, time-dependent local field enhancement at the droplet surface.

physics.plasm-ph↗

arXiv2007

Dynamics of charge-displacement channeling in intense laser-plasma interactions

The dynamics of transient electric fields generated by the interaction of high intensity laser pulses with underdense plasmas has been studied experimentally with the proton projection imaging technique. The formation of a charged channel, the propagation of its front edge and the late electric field evolution have been characterised with high temporal and spatial resolution. Particle-in-cell simulations and an electrostatic, ponderomotive model reproduce the experimental features and trace them back to the ponderomotive expulsion of electrons and the subsequent ion acceleration.

physics.plasm-ph↗

arXiv2007

Features of ion acceleration by circularly polarized laser pulses

The characteristics of a MeV ion source driven by superintense, ultrashort laser pulses with circular polarization are studied by means of particle-in-cell simulations. Predicted features include high efficiency, large ion density, low divergence and the possibility of femtosecond duration. A comparison with the case of linearly polarized pulses is made.

physics.plasm-ph↗

arXiv2007

Generation and Observation of Coherent, Long--Lived Structures in a Laser--Plasma Channel

In recent experiments of laser pulse interaction at relativistic intensities with a low density plasma, the proton radiography technique showed evidence of long--lived field structures generated after the self-channeling of the laser pulse. We present 2D particle-in-cell simulations of this interaction regime, where the dynamics of similar structures has been resolved with high temporal and spatial resolution. An axially symmetrical field pattern, resembling both soliton-like and vortex structures, has been observed. A study of the physics of such structures and a comparison with experimental data is in progress.

physics.plasm-ph↗