A field effect spacecraft neutralizer for the LISA Pathfinder mission

We outline the design, construction and testing of a field effect neutralizer, which provides a source of up to 6 mA of electron emission to maintain charge neutrality for the LISA Pathfinder mission spacecraft. The low mass, low power neutralizer uses silicon field emitter arrays and has been engineered for integration into the LISA Pathfinder micro-propulsion system. The silicon emitters are constructed using micro-fabrication techniques and electron beam lithography to ensure uniformity and precise control of emitter location. Control of the manufacture processes, plasma-enhanced vapour deposition, wet and dry plasma etch and various coatings, has been optimized to achieve robust reproducible devices suitable for space use.