Magnetic field generation and its nonlinear evolution of the Weibel instability

The Weibel instability caused by anisotropic velocity distribution may play an important role for the generation of magnetic field in the laser produc ed plasmas. A three dimensional electromagnetic and relativistic particle-i n-cell (PIC) code is used to show the generation of magnetic field and its nonlinear evolution. As a result, we confirm that strong magnetic fields ar e generated with coherent structures. Loop-like magnetic fields are generat ed in "football-shaped" anisotropy and sheet-like magnetic fields are gener ated in "pancake-shaped" anisotropy.