Conceptual Design of an Ion Microthruster

The development of a viable micro ion thruster in the millinewton range, for use on nanosatellites in the mass range 1 to 10 kg, is a task presenting many problems. Primarily this is a result of the scaling laws of the physical parameters determining the performance of these devices. Some of the major problems faced are the sustenance of a magnetic field high enough to confine the electrons to ensure economic utilization and maintenance of a pressure in the chamber such that the electron mean free path is low enough to encourage efficient ionization. A theoretical model has been used to define the bulk properties of a Kaufman- type electrostatic ion thruster. The effect of each component’s parameters on the overall thruster design was investigated and the equations presented classify a method of definitively describing a conceptual thruster from first principles. Assuming certain constraints can be satisfied, principally electron emission angle, magnetic field strength and ion extraction optics, it will be shown that the factors determining viability are compliance of a series of equations.