Filaments in high-speed counter-streaming plasma interactions driven by high-power laser pulses

Interactions of two counter-streaming plasmas driven by high power laser pulses are studied on Shenguang II laser facility. Filamentary structures were observed in the interaction region after the electrostatic shockwave decay. Theoretical analysis and observations indicate that the filaments are because of collisionless mechanisms, which are caused by the electromagnetic instability, such as the beam-Weibel instability. Collision experiments were also carried out for comparison and no filaments were generated.