Charged particle density distributions in multi-component plasmas with two species of warm positive ions

Abstract

The behavior of charged particle density distributions and the electrostatic potential in the sheath region of a multi-component plasma consisting of electrons and two species of positive ions are investigated by using a fluid description. It is assumed that the ion species are singly charged and have different masses and temperatures. To determine the ion species velocities at the plasma-sheath boundary, we used the recent work of Baalrud et al. [S. Baalrud and C. Hegna, Phys. Plasmas 18, 023505 (2011)]. It is shown that the density distributions of electrons and lighter ion species increase in the sheath region by increasing the temperature of ion species while the density distribution of the heavier ion species decreases. The results also show that by increasing the temperature of the ion species, the electrostatic potential in the sheath region decreases and at the same time the sheath thickness increases.