Interaction between electrostatic collisionless shocks generates strong magnetic fields

TL;DR

This study uses multi-dimensional Particle-In-Cell simulations to show that the collision of electrostatic shocks generates strong magnetic fields through the Weibel instability, with potential laboratory applications.

Contribution

It demonstrates the magnetic field generation during electrostatic shock collisions and links it to the Weibel instability caused by electron pressure anisotropies.

Findings

Shock velocities decrease significantly after collision.

Strong magnetic fields are generated post-collision.

The phenomenon can be replicated in laboratory settings.

Abstract

The head-on collision between electrostatic shocks is studied via multi-dimensional Particle-In-Cell simulations. It is found that the shock velocities drop significantly and a strong magnetic field is generated after the interaction. This transverse magnetic field is due to the Weibel instability caused by pressure anisotropies due to longitudinal electron heating while the shocks approach each other. Finally, it is shown that this phenomenon can be explored in the laboratory with current laser facilities within a significant parameter range.