Fig. 4: Particle-in-cell simulation results of the laser-copper plasma interaction.
From: Time-resolved X-ray imaging of the current filamentation instability in solid-density plasmas
a, b show normalized electron density maps at t = 2 ps after the laser peak intensity reaches the target surface for the collisionless (ν = 0) and collisional/resistive (ν ≠ 0) cases. The laser comes in from the left-hand side. c Lineout of the normalized electron (blue) and ion (red) density, and transverse magnetic field (black), taken at t = 2 ps and x = −3 μm, y ∈ [ −2, 2] μm for the collisional simulation. d Linear theory prediction of the growth rate Γ as a function of wavenumber k in the purely electromagnetic collisionless case (k ⋅ E = 0; ν = 0, solid black), including electrostatic effects (dashed black), and purely electromagnetic resistive case (solid red). The red and black circles indicate the simulations results in the resistive (red) and collisionless (black) cases respectively, the range markers indicate the measured distribution of dominant wavenumbers. The green marker indicates the experimental measurement, where the growth rate is approximated as the inverse of the earliest time filaments are visible in the X-ray images (Δt = 2 ps) and k is the corresponding median wavenumber. The associated range markers indicate the distribution of wavenumbers observed.
