Study of fast electron propagation in high density plasma

摘要

We present some recent work studying the propagation of the relativistic electron beams in dense targets of relevance to fast ignition. A scheme employing an external axial magnetic field is proposed to diagnose the intrinsic divergence of laser-generated fast electron beams, and this is studied with hybrid simulations. It is found that the intrinsic divergence of the fast electron can be inferred from measurements of the beam radius at different depth under the axial field. Propagation of the fast electron in the solid and high compressed target are also studied. It is shown that, for the compressed target, the self-generated magnetic field would not inverse and increase with fast electron penetration depth, leading to the collimating propagation of the fast electron in the target under an appropriate density gradient.