2011/08/04 by Dusan Jovanovic, D. Jovanović, R. Fedele +7
Engineering · Physics and Astronomy · #FOS: Physical sciences #Laser Design and Applications #Laser-Matter Interactions and Applications #Laser-induced spectroscopy and plasma #Pattern Formation and Solitons (nlin.PS) #Plasma Physics (physics.plasm-ph) #nlin.PS #physics.plasm-ph
paper · pdf · doi:10.48550/arxiv.1108.1050
Oral contribution O3.205 delivered at the 38th EPS Conference on Plasma Physics, Strasbourg, France, 26 June - 1 July, 2011
arxiv created 2011/08/04 · openalex publication_date 2011/08/04 · arxiv updated 2011/08/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The derivation is presented of the nonlinear equations that describe the propagation of ultrashort laser pulses in a plasma, in the Plasmon-X device. It is shown that the Plasmon-X scheme used for the electron acceleration uses a sufficiently broad beam (L_\bot∼ 130 μ\rm m) that justifies the use of the standard stationary 1-D approximation in the electron hydrodynamic equations, since the pulse width is sufficiently bigger than the pulse length (∼ 7.5 μ\rm m). Furthermore, with the laser power of W≤ 250 TW and the 130 μ\rm m spot size, the dimensionless laser vector potential is sufficiently small |A\bot0|2/2 = (W/c2ε0)(λ2/8 π2 c)(4/πL_\bot2)(e/m0 c)2 ∼ 0.26, the nonlinearity is sufficiently weak to allow the power expansion in the nonlinear Poissons's equation. Such approximation yields a nonlinear Schr" odinger equation with a reactive nonlocal nonlinear term. The nonlocality contains a cosine function under the integral, indicating the oscillating wake. For a smaller spot size that is used for the Thomson scattering, L_\bot = 10 μm, the length and the width of the pulse are comparable, and it is not possible to use the 1-D approximation in the hydrodynamic equations. With such small spot size, the laser intensity is very large, and most likely some sort of chanelling in the plasma would take place (the plasma gets locally depleted so much that the electromagnetic wave practically propagates in vacuum).