Langmuir Probe Measurements In Applied Research In The Diagnosis Of Mpt Plume

With incessant requirements for high performance of spacecraft propulsion system, Electric Propulsion (EP) has become a focus of spaceflight field recently because of its particular advantages, such as high efficiency, moderate Specific Impulse, long life, well compatible with spacecraft and so on. It has a wide perspective in applicationThe plume of the engine has a key effect to its applicability and reliability because the plasma consisting electrons and ions in the plume will disturb signal of electronic equipment antenna and solar board. So it is very important to develop investigation of MPT plume in all ways to design integrative spacecraft. At present MPT plume has been studied by theoretical calculation which is far from enough because it is just involved in molecule but no electron or ion investigation has done. In fact, it is extremely complicated to research the terribly little particles by means of theoretical calculation. Research to the MPT plume can be done by experimental way except theoretical calculation.Using applicable method to study MPT plume to get some characters can be called plume diagnostics. The contents of this paper include:1. On the base of the knowledge of MPT plume, it is needed to choose an applicable method to diagnostic the plume .In this paper Langmuir probe and Emissive probe were chosen because of their excellent characters.2. Technology of Langmuir probe was studied to built the Langmuir probe and Emissive probe MPT plume diagnostics system including Langmuir probe and Emissive probe working power supply system Langmuir probe Emissive probe and data collection and analyzed system. A volt-ampere curve was gained by giving Langmuir probe a variable voltage. When needed, the result of experimental could be gained immediately by the analyzed software.3. Utilizing the Langmuir probe and Emissive probe diagnostics system built up to carry the MPT plume experiment, feasibility of this method is validated. Some characters such as electron temperature -, electron density were gained and consistent to the theoretical calculation results. The research was done as a base to the coming studies.