5th INTERNATIONAL CONFERENCE ON THE FRONTIERS OF PLASMA PHYSICS AND TECHNOLOGY

18-22 April 2011, Singapore, Republic of Singapore


PLASMA SHEATH STUDIES USING THE KINETIC TRAJECTORY SIMULATION MODEL

R. Khanal, A. Awasthi, V. Kaphle and T. R. Rana

Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu, Nepal


Abstract.  Plasma sheath formed in front of a material wall for different cases have been studied. For given electron and ion distributions at the sheath entrance we use Kinetic Trajectory Simulation (KTS) model to obtain the solution to a non-neutral, time-independent, collisionless plasma sheath. The characteristic feature of the KTS method is that the distribution functions of the particle species involved are calculated directly by solving the related kinetic equations along the respective collisionless particle trajectories. For a given potential distribution, we calculate the exact ion distribution function by integrating Vlasov's equation along its characteristics and taking into account the scraping-off effect at the wall. The electron distribution, on the other hand, is calculated analytically, however taking into account the cut-off introduced by electron absorption at the wall.We also present a scheme for coupling a quasineutral two-fluid (electron-ion) presheath solution to a non-neutral, collisionless kinetic sheath solution for a 1d1v case. It has been observed that the sheath structure is highly influenced by the magnitude of potential applied to the wall. The applied kinetic model is thus expected to give better insight to the sheath phenomena.