Ion Thruster Grid Design Using an Evolutionary Algorithm

Abstract

An evolutionary algorithm was used to optimize the geometry and accelerator grid voltage of an ion thruster grid set with regard to maximizing impulse per unit area, essentially equivalent to maximizing propellant throughput capability per unit area. Grid operating conditions, including a net accelerating voltage of 1800 V and current density of 4.0 mA/cm 2 , corresponded to high-power operation of NASA's evolutionary xenon thruster. The evolutionary-algorithm-derived grid set had a predicted lifetime nearly twice that of the NASA's evolutionary xenon thruster grid set, primarily the result of a lower accelerator grid voltage magnitude.