Modelling of ion beam current density of ion thruster

The characteristics of the ion beam current density in the ion thruster, especially in the fairly wide region in the down-stream plume flow-field, was mathematically described with a semi-empirical model, based on the two existing models formulated by R. I. Samanta Roy and Thaine W. Reynolds, theoretically analyzed, numerically simulated and experimentally evaluated with the lab-built, vacuum plume effect experimental system (PES) for the 20 cm Xe ion thruster. The results, calculated with the newly-developed semi-empirical model, agree well with the measured ones. The novel model outperforms the two existing models because of its much smaller discrepancy between the calculated and measured results. We suggest that the new ion beam current density model may be of some technological interest in hybrid PIC simulation as the inlet boundary conditions and in the engineering applications, involving ion erosion and sputtered pollution.