Particle acceleration by kinetic Alfvén waves in the IO plasma torus

The generation of surface waves due to a strong gradient in the plasma density and its coupling to kinetic Alfvén waves near the Io plasma torus are found to be a viable mechanism for particle acceleration leading to a beam of energetic electrons along the magnetic field. It is shown that acceleration to a few kiloelectronvolts is possible and this might explain the intense auroral hiss observed near the inner edge of the Io plasma torus by Voyager 1.