Effects of ion source term on the sheath in electronegative dusty plasmas

Abstract

This study examines a stationary model of the magneto-electronegative dusty plasma sheath, treating dust particles as a cold fluid. In the present model, the electron and negative ion are in Maxwellian thermodynamic equilibrium, while positive ions are considered as a hot fluid with an ion source term. The effects of ion sources and ionization frequencies (IFs) on the sheath are examined to compare their contributions. A modified sheath criterion and floating potential are established theoretically using the Sagdeev potential method. The governing equations of the model are then solved numerically. The effects of the ion source on sheath electric potential, particle density, positive ion velocity, and space charge density are also investigated. It was found that the modified Bohm criterion decreases with an increase of the IF. It can be seen that the different ion source term is effective in the dusty plasma sheath structure.