Topic/Type: 2.2 Kinetic methods, Particle-In-Cell and Vlasov, Poster

### Numerical analysis of laser-plasma electron acceleration in capillary tubes.

H. E. Ferrari1, 2, A. F. Lifschitz1, 2, B. Cros1, 2

1 Laboratoire de Physique des Gaz et des Plasmas, Universit? de Paris Sud
2 CNRS

Capillary tubes can be used to guide ultraintense and short lasers in cm long plasmas [1], this means several Rayleigh lengths. The laser pulse can excite a plasma wave with a several GV/m longitudinal electric field. Electrons could be externally injected or internally injected and accelerated in this field.
We have used two tools to analyze the problem, the code Wake for fast simulations and a 3D PIC code for full simulations. Wake was used to explore experimental parameters and to find regions with trapping. For the full simulations, we have adapted a quasi 3D Particle in Cell code that models laser plasma interaction [2] to implement the capillary tube. Fourier decomposition is used for the electric and magnetic fields. This accelerates the code to give a performance similar to 2D PIC codes. A non-uniform dielectric function ($\small \epsilon$) is used to simulate the propagation of the laser in the capillary tube. $\small \epsilon$ is equal to 1 for vacuum, 2.25 for glass and a quadratic increasing function is matched to the capillary external radius to speed up the code. Experimental values of laser profiles and plasma densities are used. Numerical results are compared with experimental values.

[1] B. Cros et al, ?Eigenmodes for capillary tubes with dielectric walls and ultraintense laser pulse guiding?, Phys. Rev. E, (65) , 026405

[2] A. Lifschitz et al, "Particle in cell modelling of laser plasma interaction using Fourier decomposition? , Journal of Computational Physics, doi: 10.1016/j.jcp.2008.11.017