Book Description

Results are presented for a theoretical analysis of the performance of two-grid accelerator systems for Kaufman thrusters. Six configurations were used to cover the range of geometries which are of immediate interest. A digital ccomputer program was used to find axially symetric solutions for a single hole of each configuration. Results are presented in terms of maximum current per hole, thrust per hole (including beam divergence effects), and maximum net-to total-voltage ratio consistent with the prevention of electron backstreaming. The results presented herein should be useful in the design of accelerator systems for a variety of applications. An analysis of the effects of charge-exchange ions on the erosion rate of the accelerator grid resulted in equations which could be used to predict the expected useful lifetime of the grid. The equations seemed consistent when theoretical results were compared with experimental results for the SERT II configuration. However, when applied to the configurations used in this analysis, limitations in the usefulness of the model were found and are presented herein.