Numerical Solution of the Ionization Equations by Step Fractions

The fractional steps method is applied to solve electron-ion plasma ionization equations involving neutrals, with a focus on processes in stationary plasma thrusters (SPT). The approach is based on splitting by physical processes: plasma evolution is represented as a superposition of pure transport in an external field in phase space followed by ionization. The particle-in-cell method is used for calculating transport. In the case of planar symmetry, the ionization process is calculated using explicit analytical formulas. The derived formulas of the fractional steps method are compared with the numerical solution of the plasma evolution equation through a well-known physical ionization model.