In-orbit demonstration of an iodine electric propulsion system.

Propulsion is a critical subsystem of many spacecraft. For efficient propellant usage, electric propulsion systems based on the electrostatic acceleration of ions formed during electron impact ionization of a gas are particularly attractive. At present, xenon is used almost exclusively as an ionizable propellant for space propulsion.

Ion beam diagnostic for the assessment of miniaturized electric propulsion systems.

An automated plume diagnostic system is presented for two-dimensional mapping of the ion beam produced by using miniaturized electric propulsion devices. The instrument is designed to operate with noble and reactive gases and consists of a semi-circular probe array with a unique angular distribution following a Gaussian shape for improved beam profile resolution. To demonstrate the operation of the diagnostic system, a series of experiments are conducted with a low-power gridded ion thruster using xenon and iodine propellants.

Magnetized retarding field energy analyzer measuring the particle flux and ion energy distribution of both positive and negative ions.

This paper presents the development of a magnetized retarding field energy analyzer (MRFEA) used for positive and negative ion analysis. The two-stage analyzer combines a magnetic electron barrier and an electrostatic ion energy barrier allowing both positive and negative ions to be analyzed without the influence of electrons (co-extracted or created downstream). An optimal design of the MRFEA for ion-ion beams has been achieved by a comparative study of three different MRFEA configurations, and from this, scaling laws of an optimal magnetic field strength and topology have been deduced.

Empirical laws of particle extraction from single-grid source of bipolar ion-electron flow.

The present research is devoted to the problem of extraction grid choice for a single-grid source of bipolar ion-electron flow. The paper contains detailed reference information on ion and electron extraction characteristics of 10 different grids with broad range of parameters: aperture width (0.09-0.

High homogeneity 25 cm low-energy rf ion source with inherent electron compensation.

A 25 cm single-grid low-energy rf ion source with inherent electron compensation is described and characterized. Measurements were carried out using Ar and CF(4) filling gas. The dependence of the ion beam current to the target as well as the current partition between the beam fast and slow ions on the rf discharge pressure for both filling gases is discussed.