Electromagnetic fields in nonlinear magnetosonic waves with relativistic propagation speeds

The structure of nonlinear magnetosonic waves with relativistic propagation speeds is studied through theory and particle simulation. First, the maximum values of magnetic and transverse electric fields and electric potential are analytically obtained as a function of the Alfven speed and Mach number, under the assumption that waves propagate nearly steadily in the direction perpendicular to a magnetic field. Then, one-dimensional, relativistic, electromagnetic particle code with full ion and electron dynamics is used to study relativistic magnetosonic waves. Tt is found that the ion currents parallel to the the wave front become comparable to the electron currents in magnitude. As the propagation speed is increased. transverse fields become dominant components in electromagnetic fields of a wave. The theoretically obtained values of field quantities are in good agreement sith the simulation results.