Collisional effects on the process of phase mixing of electron–positron oscillations in multispecies plasmas.

The electron–positron oscillations (EPOs) around fixed massive ions in cold electron–positron–ion (EPI) plasmas mix up in phase and break at arbitrarily small amplitudes (C Maity, Phys. Plasmas21, 072317 (2014)). In the present paper, we report the collisional effects on the process of phase mixing of EPOs in such plasmas. For our purpose, we assume that the electrons and positrons suffer collisions with the static ions. A perturbation treatment of the basic equations is carried out to derive an expression for phase-mixing time. The phase-mixing time depends on the equilibrium ion to electron density ratio, the perturbation amplitude and the rate of collisions. The collisional effects are found to delay the overall phase mixing process of EPOs. [ABSTRACT FROM AUTHOR]