Pickup Ion Injection and Acceleration at Perpendicular Shocks

Abstract

Results from a multiscale hybrid kinetic simulation of low plasma beta supercritical perpendicular shocks are presented. Freshly ionized pickup ions are included self-consistently. It is found that perpendicular shocks can accelerate pickup ions from an initial thermal" shell distribution to high energies. The mechanism by which the pickup ions are energized is that of multiply reflected ion (MRI) acceleration Zank et al., 1996; Lee et al., 1996 . The injection efficiency is found to be very high and maximum energies of nearly 0.5 MeV are attained. MRI acceleration may provide a solution to the so-called injection problem for anomalous cosmic rays.