Modeling of stationary plasma thruster-100 thruster plumes and implications for satellite design

A computational model of a stationary plasma thruster (SPT) has been develo ped using a quasineutral particle-in-cell/direct simulation Monte Carlo (PI C-DSMC) model. This model is based on theoretical work showing that the plu me consists of a quasineutral plasma with collisionless electrons in which the magnetic field can be neglected. Details of the PIC-DSMC method are pre sented as well as axisymmetric and three-dimensional results. Comparisons a re made to new and previously reported experimental data. The model is show n to produce results similar to laboratory measurements of the ion current density and plume-induced sputter erosion rates. The model does not compare as well with retarding potential analyzer measurements of the ion energy d istribution, The results confirm previous observations that measurements ma de in some ground facilities may substantially overpredict the amount of ba ckflow current that will be experienced under operational conditions, A sur face-sputtering model is used to predict the impact the plume has on solar array interconnects and to show the impact an SPT thruster could have on a communications satellite. The results show that the thruster should be cant ed with respect to the solar array, lowering its effective thrust and speci fic impulse.