Dr. Pablo MartinDepartment of Physics, University of Antofagasta, Chile
Speech Title: Improved analytic solution for the joint sheath and presheath potentials
Abstract: An analytic function is presented as a joint solution for the wall potential in both sheath and presheath region. The solution is designed as a bridge joining the conditions imposed by the Bohm differential equation near the wall, and those due to the plasma, where the potential an electric field must be zero. The new proposed function allows to determine the characteristic Bohm velocity, once the wall potential is given. The results now obtained are physically more convenient than those could be obtained through a recent publication . The parameters of the new potential are derived by the analysis of the Bohm differential equation near the wall. However the later unphysical behavior of the exact solution of this differential equation further away of the wall, is not present now.
 P. Martin, F. Maass, F. Calderon and F. Lastra, Physica Scripta 94 (2019) 015602.