Generation of wakefields by electromagnetic waves in a magnetized electron-positron-ion plasma

The generation of electrostatic wakefields by an ordinary mode radiation and a magnetic field-aligned circularly polarized electromagnetic (CPEM) wave in a magnetized electron-positron-ion (e-p-i) plasma is considered. It is found that the presence of the ions is essential for the generation of upper-hybrid wakefields by the ordinary mode radiation, while the magnetic field-aligned electron plasma wakefields are created by the ponderomotive force of CPEM only if either the ions or the external magnetic field is present in an e-p-i magnetoplasma. The electromagnetic wave generated wakefields can trap both the electrons and the positrons and accelerate them to very high energies.