A Monte Carlo Simulation Of Electron Drift Limited By Collisions In Gas Mixtures Using The Null Collision Method
The Monte Carlo method is explored as an alternative to expansion solutions of the Boltzmann transport equation for determining electron swarm parameters. This method uses the probability P that the time of flight of an electron is less or equal to some time T, and the time T. The null collision method proposed by Skullerud (1968) and developed in detail by Reid (1979) takes advantage of the simple relationship between the time of flight T and the probability of having a collision P for a cross section that is inversely proportional to the velocity. A null collision cross section is added to real cross sections so as to impose this relation. Once the time of flight is established, then the position and the energy of the electron are also defined. A new random number R is generated to determine which type of collision event takes place. When two gases are present in the simulation the following conditions determine the type of collision that takes place.