A 9700-hour durability test of a five centimeter diameter ion thruster

Abstract

A modified Hughes SIT-5 thruster has been life-tested at the Lewis Research Center. The final 2700 hours of the test are described with a charted history of thruster operating parameters and off-normal events. Performance and operating characteristics were nearly constant throughout the test except for neutralizer heater power requirements and accelerator drain current. A postshutdown inspection revealed sputter erosion of ion chamber components and component flaking of sputtered metal. Several flakes caused beamlet divergence and anomalous grid erosion, causing the test to be terminated. All sputter erosion sources have been identified and promising sputter resistant components are currently being evaluated.

Durability Tests of a 5-cm-diam Ion Thruster System

“…Details of the electrical system, automatic digital data acquisition system, protective control system, and test procedures are described in Ref. 5. The thruster was operated open-looped at nominally fixed conditions with minor day-to-day adjustments.…”