Neutralization of the extracted ion beam is a mandatory task for any ion thruster based space mission. The required lifetimes are in the order of ten thousand hours. This requirement is fulfilled by hollow cathodes operating with xenon, but has not been demonstrated for operation with iodine yet. Furthermore, the power consumption as well as the demand on mass flow should be kept as low as possible. Since the halogen iodine seems to be a viable alternative to xenon for operating ion thrusters, a suitable neutralizer concept that can operate with the corrosive gas for the time periods stated above is required. We propose to use a neutralizer based on an inductively coupled rf discharge as alternative to hollow cathodes. We studied the performance of a prototypical neutralizer operating with iodine as well as the inert gases xenon and krypton and compared the experimental studies with the results of global modeling.
Long lifetime hollow cathodes for 30-cm mercury ion thrusters