Particle-in-cell simulation of the pulsed planar expansion of a fully ionized plasma off a surface

Using particle-in-cell computer simulation, the expansion of a plasma formed by isothermal evaporation of ions and electrons off a planar wall into a vacuum is investigated. The hydrodynamical and electrical characteristics of the ion and electron expansion flow during and after the emission phase are analyzed. Ion acceleration is investigated in detail. While during the emission phase a considerable part of the electron energy is stored in thermal motion, and cannot be converted to ion energy, this conversion happens almost completely in the post-emission phase. As a result, the velocity distribution of ions is increased at large velocities by several orders of magnitude.