MAGNETIC FIELD GENERATION IN ANISOTROPIC RELATIVISTIC PLASMA REGIMES

The Weibel instability (and its beam-plasma counterpart: the current filamentation instability) is an electromagnetic instability that generates a magnetic field in the presence of particle phase-space anisotropies. These instabilities have been investigated in the case of ultra-intense and ultra-short laser pulses interacting with a plasma, but are also of primary importance in the astrophysical context relating to the formation (or to the seeding at small spatial scales) of magnetic fields. Here we shall investigate what are the typical spatial scales and structures of the magnetic field that can be expected to be generated by the development of the current filamentation instability.