Production of High Current Density Ion Beams by Electrohydrodynamic Spraying Techniques

摘要

The production of high current density ion beams by the direct interaction of an intense electric field on a liquid surface was investigated. Electrohydrodynamic spraying techniques, which have been traditionally utilized for the production of multi-molecular charged particle beams, were optimized for the production of ionic particles. Simultaneous ion formation and acceleration was achieved by applying a high DC voltage between a hemispherical liquid meniscus supported at the tip of a metallic capillary and a concentric, planer accelerating electrode. The field evaporated particles were analyzed to determine the usefulness of this technique as a source of charged particles for electrostatic microthrusters. The total emitted current, specific charge distribution of the emitted particle, and formation energy of the particles were measured in terms of the operating parameters of the system. Stable ion currents of up to 500 microamps were obtained from a single capillary emitter. The ion beam consisted of 75% gallium dimers, 24% indium dimers and 1% gallium tetramers. The resulting thrust produced was 73.8 micronewtons. (Author)