BALLISTIC WAKE OF TURBULENCE IN A PLASMA SHOCK WAVE

The role of ballistic term in the turbulence that occurs in plasma shock waves is discussed. For electrostatic turbulence these terms are shown to give rise to a wake behind a shock wave in which the energy density in the fluctuating fields decays spatially as x-3 for a class of distribution functions including resonance functions. The importance of the ballistic transport of turbulent fields inside shocks is also pointed out. This occurs because in such structures there is usually not enough length scale for these fields to phase mix away. Thus, the use of conventional quasilinear theory (which neglects these effects) will often be inadequate to describe even weak turbulence in a shock wave.