Modulation instability in relativistic laser plasmas

The modulation instability of self-generated magnetic field in the super strong relativistic laser-plasma interactions was investigated from a set of nonlinear kinetic governing equations taking into account of the wave-wave, wave-particle interactions and the relativistic effect of electrons. On the basis of the nonlinear kinetic governing equations, the dispersion equation of transverse perturbation was obtained through linear analysis. Theoretical analysis and numerical calculation indicate the spontaneous magnetic field will collapse and form a localized structure. Choosing appropriate parameters, the characteristic scale of magnetic field obtained from numerical calculation is consistent with the existing theoretical model.