A theoretical study of a uniform fast electron beam propagating in plasma density gradient targets (low density core-high density cladding) is presented. The self-generated magnetic field is calculated using a rigid beam model in cylindrical geometry. It is found that the spontaneous magnetic field peaks at the interface and penetrates into the inner target. This method is used for reducing the transverse angular distribution of a fast electron beam (control of the divergence of fast electron beams). The numerical analysis showed that a low density core–high density cladding structure target in Cartesian geometry can also generate a mega gauss interface magnetic field, which collimates fast electrons.
