Electron acceleration in the front of intense collisionless shock waves

The magnetohydrodynamic analysis of the structure of intense shock waves propagating across the magnetic field in a collisionless plasma, showed that for Mach numbers higher than critical the wave profile overturns and a multivelocity ion stream forms. In the kinetic description it corresponds to the situation when part of the ions of the oncoming plasma flow is reflected from the electrical potential jump in the shock front. Direct measurements of plasma parameters and lower-hybrid oscillation intensity at the bow shock forming in the supersonic solar wind in front of the Earth magnetosphere, have confirmed that the mechanism of energy dissipation, sometimes accompanied by the anomalous ion-sound viscosity, is a basic mechanism in case of strong collisionless shock waves and may explain the observed ion thermalization behind the shock front.