Sh Amiranashvili

Institute for Theoretical and Experimental Physics, Moskva, Moscow, Russia

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Publications (11)21.06 Total impact

  • Sh Amiranashvili, M Y Yu
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    ABSTRACT: Lagrangian variables are used to describe both surface and volume nonlinear oscillations of spatially bounded plasmas. Simple exact, or nonperturbative, solutions can often be obtained for complicated problems. Here, several recent analytical results on nonlinear standing waves in bounded systems are reviewed. These include temperature effects on nonlinear standing waves, oscillations of expanding multi-species plasma, and phase locking and transition to chaos. The analytical solutions are in good agreement with that from particle-in-cell simulation. The exact solutions are also useful as starting point and verification for novel perturbation or numerical schemes, as well as stability analysis. They are of particular interest with respect to electromagnetically trapped nonneutral as well as freely expanding plasmas.
    Physica Scripta 04/2006; 2004(T113):9. · 1.03 Impact Factor
  • Sh Amiranashvili, M Y Yu, L Stenflo
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    ABSTRACT: An analytical model for breathing oscillations in a nonuniform non-neutral plasma slab is developed. The plasma is relatively small and warm with the smallest dimension only of several Debye lengths. Nonuniformity in the equilibrium results in a frequency shift associated with pressure and boundary effects. The plasma size and temperature, being related to the frequency shift, can therefore be evaluated from frequency measurements. In particular, for small nonuniform plasmas the frequency of the breathing mode is twice that predicted by the cold fluid theory. Nonlinear oscillations are also considered and the pressure is shown to have an important effect on the dynamics. Analytical solutions for linear and nonlinear oscillations are obtained and compared with that from one-dimensional particle-in-cell simulations. Good agreement is found.
    Physical Review E 02/2003; 67(1 Pt 2):016408. · 2.31 Impact Factor
  • Sh. Amiranashvili, M. Y. Yu, L. Stenflo
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    ABSTRACT: Lagrangian variables are used to describe linear and nonlinear oscillations of a magnetized non-neutral plasma slab in a harmonic trap, for slab width larger or comparable to the Debye length. The plasma particles move along the magnetic field lines, so that the oscillations are one-dimensional. The oscillation spectrum is found analytically, and the thermal corrections to the frequencies are calculated in a nonperturbative manner. Simple exact nonlinear solutions for the low-order modes are also obtained.
    Physics of Plasmas 01/2003; 10:1239-1242. · 2.38 Impact Factor
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    Sh Amiranashvili, M Y Yu, L Stenflo, G Brodin, M Servin
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    ABSTRACT: An analytical model for nonlinear volume oscillations in a bounded cold plasma is developed. Although here the familiar propagating wave solutions do not exist, exact nonlinear standing waves subject to appropriate boundary conditions can nevertheless be found. The behaviors of the electrons and ions are described self-consistently in terms of Lagrangian variables. The analytical solutions are compared with that from particle-in-cell simulations. Good agreement is found in the regimes of interest.
    Physical Review E 11/2002; 66(4 Pt 2):046403. · 2.31 Impact Factor
  • Sh. Amiranashvili, M. Y. Yu
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    ABSTRACT: Ambipolar diffusion of electrons and ions in a plasma containing charged dust grains is investigated. As the diffusion is on the ion time scale, the dust distribution remains stationary but the dust charge can vary. An analytical solution showing that the presence of dusts can significantly increase the diffusion length is given. Other solutions of practical interest are obtained numerically. © 2002 American Institute of Physics.
    Physics of Plasmas 10/2002; 9(11):4825-4828. · 2.38 Impact Factor
  • Sh Amiranashvili, M Y Yu, L Stenflo
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    ABSTRACT: A non-neutral plasma column in an asymmetric trapping field is considered in this paper. It is shown that nonlinearly interacting bulk plasma oscillations and quadrupole surface waves allow an exact analytical description. The absence of symmetry leads to nonintegrability and other nonlinear phenomena, such as passage through different resonances and phase locking. These phenomena should be observable in experiments involving elliptical traps and rotating walls and can affect the latters' applications.
    Physical Review E 05/2002; 65(4 Pt 2B):046402. · 2.31 Impact Factor
  • S G Amiranashvili, N G Gusein-zade, V N Tsytovich
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    ABSTRACT: A monolayer dusty crystal can be observed in the glow discharge. In particular, a small number of dusty grains form simple atom-like plane clusters. Stability and oscillations of the polygonal cluster are considered. For the simplest stable clusters normal displacements and frequencies are found for an arbitrary form of mutual interaction. The measurement of these modes can help to give in detail the form of the potential function.
    Physical Review E 08/2001; 64(1 Pt 2):016407. · 2.31 Impact Factor
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    A M Ignatov, S G Amiranashvili
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    ABSTRACT: It is shown that inhomogeneous heating of the dust grain by ion flow in a glow discharge results in a photophoresislike force. According to our estimations, this radiometric force can be comparably-valued with the ion-drag force under the conditions of microgravity dusty plasma experiments.
    Physical Review E 02/2001; 63(1 Pt 2):017402. · 2.31 Impact Factor
  • SG Amiranashvili
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    ABSTRACT: A uniform density ellipsoid is an equilibrium state of a low-energy non-neutral plasma confined in a harmonic trap. Normal modes of this plasma can be detected; they provide a nondestructive diagnostic tool. The low-order quadrupole modes are particularly simple. They can be calculated analytically even in a nonlinear regime. In general, nonlinear coupling leads to the complicated stochastic dynamics. In special cases, regular solutions can be found. It is shown that the behavior of an elongated ellipsoid oriented along the trap symmetry axis is nearly integrable. The study results in simple analytical expressions for frequencies and ellipsoid semiaxes.
    Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics 08/2000; 62(1 Pt B):1215-23.
  • Sh. G. Amiranashvili
    Plasma Physics Reports 01/1999; 25:846-854. · 0.66 Impact Factor
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    Sh. Amiranashvili, N. Gusein-Zade, A. Ignatov
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    ABSTRACT: The stability of polygonal patterns composed of a set of N point charges in a potential well is studied. It is shown that a right polygon is stable for N
    Physical Review A 01/1999; 59(4):3098-3100. · 3.04 Impact Factor