Simulation of a Cloud-Cloud Collision in an Electron-Positron Plasma

Abstract

The dynamics of the clouds in magnetized plasmas is one of the basic processes found in many areas ranging from astrophysical to laboratory plasmas. This cloud dynamics in electron-ion and electron-positron plasmas has been investigated theoretically (Peter and Rostoker, 1982) and by using particle simulations (Galvez, 1987; Neubert. et al., 1992; Kitanishi et al., 1994). Results of these simulations have shown that (1) the cloud keeps moving across an ambient magneticfield as E × B drift, (2) electron and ion (positron) charge sheaths expand along the magnetic field, and (3) electromagnetic waves are emitted from the cloud due to the coherent gyration of particles. For the case of electron-positron plasma in strong magnetic field, the kinetic energy of the cloud is very efficiently transformed into the emitted wave energy (Kitanishi et al., 1994).