Collective Ion Acceleration by Relativistic Electron Rings in the Magnetosphere

To Professor Arnulf Schlüter on his 60th Birthday Calculations are presented which show that the collective acceleration of ions by rings of relativistic electrons seems feasible in the polar regions of a dipolar magnetospheric field. The well known magnetic field of the earth is taken as an example and it is found that with rings of electrons of only 4 MeV initial energy, deuterons can be accelerated up to energies of about 50 MeV from rest in a distance of one third of an earth radius. Although the drift motion of the electron rings across the magnetic field lines is negligible for latitudes greater than 45°, in the equatorial plane the ring drifts at constant altitude with a speed proportional to the local magnetic field index.