Investigation of Capillary Discharge Ionization

摘要

The primary aim of this program is the investigation of capillary discharge ionization and evaluation for use in electric propulsion. The investigation includes the formulation of theoretical models to predict operational modes, and the performance of suitable experimentation to observe phenomena and verify the theory. The program is based upon the examination of capillary discharge ionization which occurs when gas is bled into a vacuum through a small cap illary nozzle, elevated to a high electrical potential. With the gas flow and the applied electric field at a sufficiently high level, the discharge occurs at the tip of the nozzle and ions are generated. These ions are accelerated by the potential difference between the nozzle and extractor electrode planer to the nozzle and at ground or slightly negative potential. The ions form a narrow beam. The discharge is accompanied by a visable glow of light whose color (spectrum) reveals the particular type of gas input.