NOZZLE ARRANGEMENT FOR USE IN A GAS THRUSTER, GAS THRUSTER, METHOD FOR MANUFACTURING A NOZZLE ARRANGEMENT, METHOD FOR IN-SITU REPAIRING OF A NOZZLE ARRANGEMENT AND A METHOD FOR OPERATING A GAS THRUSTER

摘要

A nozzle arrangement for use in a gas thruster is presented. At least one heater micro structure (20) is arranged in a stagnation chamber (12) of the gas thruster. The heater microstructure (20) comprises a core of silicon or a silicon compound coated by a surface metal or metal compound coating. The heater microstructure (20) is manufactured in silicon or a silicon compound and covered by a surface metal coating. The heater microstructure (20) is mounted in the stagnation chamber (12) before or after the coverage of the surface metal or metal compound coating. The coverage is performed by heating the heater microstructure and flowing a gas comprising low quantities of a metal compound. The compound decomposes at the heated heater microstructure (20), forming the surface metal or metal compound coating. The same principles of coating can be used for repairing the heater microstructure (20) in situ. The driving gas comprises preferably a compound exhibiting an exothermic reaction when coming into contact with a catalytically active material. If the gas is exposed to heater microstructures being covered with the catalytically active material, the gas is further heated by the catalytic reaction.