A Model of Secondary Emission and Its Application on the Charging of Dust Grains

Dust grains of various shapes and materials can be found anywhere in the space where the temperature decreases under a melting point. Many plasma processes are driven by the grain charge but, on the other hand, dust grain charging can be influenced by several different processes, too. Among others, secondary emission can play a dominant role wherever the plasma is hot. In the present paper, a further development of our previous simple numerical secondary emission model, now using techniques for a beam interaction modelling applied in electron microscopies, is sketched and its application onto charging of spherical dust grains by a narrow electron beam is discussed. The model fits experimental data rather well and, thus, our conclusion suggests that the model is a very useful tool for considerations on the dust charging under different conditions in the space.