Grid design improvements and test philosophy for a cost-effective approach to ion thruster qualification

摘要

The development of a grid erosion computer model can produce a cost-effective approach to ion thruster qualification, most especially when confidence in the model has been established as a result of several long duration tests. However, consideration must be given to operating conditions, such as mass utilisation, anode voltage and facility pressure if the test results are to be used to improve and validate the model. This technique of a limited long duration test (2000 hours) and a grid erosion model has been applied to the UK-10 ion thruster on ARTEMIS. The result is a grid set design which is optimised for maximum lifetime based primarily on two 500 hour tests performed previously. The limited long duration test is due to start early in 1996. The advantage of this approach is that the design has been optimised without a major investiment in a test programme, and the output from the test programme will result in further improvements to the model, so giving good confidence in extrapolations of thruster lifetime.