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Academic year: 2021

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ABSTRACT

Among the various components characterizing a cathode neutralizer, the heater has a fundamental role in the reliability and performance of such kind of electron source. The development of a heater is a significant technological challenge tied with the need of reaching high ignition temperatures (1500-2000 K) minimizing the power consumption and reducing the heat losses during nominal operation.

The present work describes the study of a heater for hollow cathode neutralizers, with the aim of providing guidelines for the design of the heating system composed by heater, electrical and thermal insulation.

After a brief introduction on space propulsion and hollow cathodes, in the first part of the thesis two different heating systems are studied, alternative to the classical ohmic resistance, namely conduction and induction heating. For each heating procedure, a physical model and a numerical simulation have been developed using the software Comsol Multiphysic® 3.4. Afterwards, the design of a coiled wire electrical resistance is performed, analyzing the possibility of radiation heating.

Finally, the choice of the electrical insulation is presented, as well as the

conclusions.

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