3,526 research outputs found
A strategy to suppress recurrence in grid-based Vlasov solvers
In this paper we propose a strategy to suppress the recurrence effect present
in grid-based Vlasov solvers. This method is formulated by introducing a cutoff
frequency in Fourier space. Since this cutoff only has to be performed after a
number of time steps, the scheme can be implemented efficiently and can
relatively easily be incorporated into existing Vlasov solvers. Furthermore,
the scheme proposed retains the advantage of grid-based methods in that high
accuracy can be achieved. This is due to the fact that in contrast to the
scheme proposed by Abbasi et al. no statistical noise is introduced into the
simulation. We will illustrate the utility of the method proposed by performing
a number of numerical simulations, including the plasma echo phenomenon, using
a discontinuous Galerkin approximation in space and a Strang splitting based
time integration
Vlasov simulation of laser-driven shock acceleration and ion turbulence
We present a Vlasov, i.e. a kinetic Eulerian simulation study of nonlinear
collisionless ion-acoustic shocks and solitons excited by an intense laser
interacting with an overdense plasma. The use of the Vlasov code avoids
problems with low particle statistics and allows a validation of
particle-in-cell results. A simple original correction to the splitting method
for the numerical integration of the Vlasov equation has been implemented in
order to ensure the charge conservation in the relativistic regime. We show
that the ion distribution is affected by the development of a turbulence driven
by the relativistic "fast" electron bunches generated at the laser-plasma
interaction surface. This leads to the onset of ion reflection at the shock
front in an initially cold plasma where only soliton solutions without ion
reflection are expected to propagate. We give a simple analytic model to
describe the onset of the turbulence as a nonlinear coupling of the ion density
with the fast electron currents, taking the pulsed nature of the relativistic
electron bunches into account
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