ION ACCELERATOR DESIGNS FOR KAUFMAN THRUSTERS

Effects of varying the geometric parameters of a two-grid ion accelerator system for Kaufman thrusters are presented in terms of ion beam optics and accelerator grid lifetime. Results were obtained for a single hole model using a digital computer program and an electrolytic tank analog. The geometric parameters investigated include the grid thicknesses, grid hole diameters and spacings, and grid separation distances. Other variables which affect the optics and the lifetime are then discussed. These variables include open-area fraction of the screen, geometric scaling, total voltage, net/total voltage ratio, propellant utilization efficiency, over-all grid diameter, and total number of grid holes. The results presented can serve as guidelines for designing future two-grid accelerator systems. Also included are new techniques for obtaining the shape and location of the downstream plasma boundary and for predicting the minimum accelerator potential needed to prevent electron backstreaming. © 1969 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.