| Popis: |
Particle in cell (PIC) modelling is a computational technique which functions by advancing computer particles through a spatial grid consisting of cells. This computational method is useful for simulating plasma and is able to yield detailed results such as particle number densities, particle energies, currents and electric potentials. The ability to provide such detailed results makes this computational method ideal for simulating the plasma within the discharge chamber of an ion thruster. This work focuses on the PIC algorithm and its application in a plasma simulation; however, and not on ion thruster simulation. Unfortunately, the detailed results of a PIC simulation come at a substantial cost of computational requirement. The goal of the work presented here is to develop techniques which allow the PIC algorithm to ease stability restrictions on time step size. Two techniques are investigated: solving for the electric field multiple times within one time step and using a fourth order polynomial to represent the electric field. For each of these techniques, the computational time required for a single time step increases, but the overall computational time may be reduced. In their present form, these techniques do not allow for a larger time step to be utilized. However, several suggestions are made within this paper which may allow these techniques to be successful in future work. |
