Evolution of magnetohydrodynamic waves and acceleration of particles in a collision of two plasmas

Electron acceleration in magnetohydrodynamic waves produced by a collision of two high-temperature plasmas in an external magnetic field B-0 is Studied with particle simulations. First, possible particle motions that traverse multiple layers with alternating magnetic polarity are illustrated. Then, it is shown with one-dimensional. fully kinetic, relativistic, electromagnetic particle simulations that as a result Of plasma collision, a large-amplitude Alfven wave packet can be formed behind a magnetosonic shock wave. In the wave packet with alternating magnetic polarity, some electrons exhibit Orbits predicted by the physical considerations and are accelerated to high energies Such that gamma > 100. It is thus found that the Alfven wave packet as well as the magnetosonic shock wave can create ultrarelativistic particles with its strong wave fields.