425 research outputs found
Relativistic laser-matter interaction and relativistic laboratory astrophysics
No full textThe paper is devoted to the prospects of using the laser radiation interaction with plasmas in the laboratory relativistic astrophysics context. We discuss the dimensionless parameters characterizing the processes in the laser and astrophysical plasmas and emphisize a similarity between the laser and astrophysical plasmas in the ultrarelativistic energy limit. In particular, we address basic mechanisms of the charged particle acceleration, the collisionless shock wave and magnetic reconnection and vortex dynamics properties relevant to the problem of ultrarelativistic particle acceleration
Stability of a plasma foil in the radiation pressure dominated regime
No full textThe stability of a thin plasma foil accelerated to relativistic velocities by the radiation pressure of an ultra high intensity electromagnetic pulse is investigated. The effects of the onset of a Rayleigh-Taylor-like instability are discussed in the context of the ion acceleration process during the interaction of the laser pulse with the plasma. It is stressed that the experimental study of this advanced laser plasma interaction regime will be accessible within the framework of the ELI experiment and will be of relevance for our understanding of high energy astrophysical phenomena
Charged particle dynamics in multiple colliding electromagnetic waves. Survey of random walk, Levy flights, limit circles, attractors and structurally determinate patterns
No full textThe multiple colliding laser pulse concept formulated by Bulanov et al. (Phys. Rev. Lett., vol. 104, 2010b, 220404) is beneficial for achieving an extremely high amplitude of coherent electromagnetic field. Since the topology of electric and magnetic fields of multiple colliding laser pulses oscillating in time is far from trivial and the radiation friction effects are significant in the high field limit, the dynamics of charged particles interacting with the multiple colliding laser pulses demonstrates remarkable features corresponding to random walk trajectories, limit circles, attractors, regular patterns and Levy flights. Under extremely high intensity conditions the nonlinear dissipation mechanism stabilizes the particle motion resulting in the charged particle trajectory being located within narrow regions and in the occurrence of a new class of regular patterns made by the particle ensembles.Office of Science of the US DOE [DE-AC02-05CH11231]; National Basic Research Program of China [2013CBA01502]; NSFC [11535001]; National Grand Instrument Project [2012YQ030142]SCI(E)ARTICLE8
Formation of electromagnetic postsolitons in plasmas
No full textWith particle-in-cell simulations we show that electromagnetic relativistically strong solitons, formed in the wake of the laser pulse, during the interaction of a high-intensity ultrashort laser pulse with a collisionless plasma, evolve asymptotically into postsolitons. A postsoliton is a slowly expanding cavity in the ion and electron densities which traps electromagnetic energy. Fast ions are accelerated during the postsoliton formation. Postsolitons are elementary components of the relativistic electromagnetic turbulence in laser-irradiated plasmas
Fast collisionless magnetic reconnection: Fluid regime and kinetic effects
No full textCollisionless magnetic field line reconnection exhibits important similarities under widely different physical conditions. ranging from the magnetohydrodynamic regime, of interest for space and high temperature magnetically confined plasmas, to the electron-magnetohydrodynamic regime, of interest for the interaction of ultraintense, ultrashort laser pulses with a plasma. Analytical and numerical results are presented that illustrate the nonlinear evolution of the reconnection instability in a two dimensional configuration with a neutral line in fluid and in kinetic plasma regimes. The importance of plasma anisotropy is stressed for the case of laser plasma interaction
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