A COMPUTER EXPERIMENT TO STUDY THE CHARGING PROCESS FOR DUST GRAINS IN THE PLASMA

Abstract

Dust grain in plasma is charged up by collecting electrons and ions from the plasma, this charging process has been studied for laboratory dusty plasma. The Orbital Motion Limited theory predicts the electron and ion currents toward the grain, the discrete charging model uses these current values and converts it to probabilities for collecting individual electrons and ions, this model assumed that discrete charges will be collected at random intervals in a random sequence.A program with FORTRAN programming language has been built to translate the discrete model to simulate the charging process. Then, the value of the charge number and their fluctuations as a function of time, charging time and mean equilibrium charge number on the grain surface have been predicted. It has been concluded that the grains were charged with negative and the charging process, in general, was affected by grain size, electron temperature, and the background plasma type.