AbstractThe effect of secondary electron emission and sputtered impurity ions on the sheath potential drop has been studied. An analytical model has been developed which allows a self‐consistent description of the above mentioned effects. In the analysis different materials (two kinds of graphite and tungsten) have been compared and a considerable dependence of the potential drop on the material choice has been observed. It is shown that the most of energy coming from the plasma to the target is carried by electrons because of both the decrease of potential drop caused by SEE and the enhancement of electron current to the plate caused by sputterin