Research on the neutralization control of the RF ion micropropulsion system for the ‘Taiji-1’ satellite mission

Abstract

To achieve the neutralization control requirements of the radio-frequency (RF) ion microthruster (μRIT) in the 'Taiji-1' satellite mission, we proposed an active neutralization control solution that is based on the carbon nanotube field emission technology. The carbon nanotube field emission neutralizer (CNTN) has the characteristics of light weight, small size, and propellantless, which is especially suitable for the neutralization control tasks of ion microthrusters. The Institute of Mechanics, Chinese Academy of Sciences, in collaboration with Tsinghua University, has successfully developed a CNTN to meet mission requirements. On the ground, the feasibility of cooperation working between μRIT and CNTN was fully verified, as well as the simulation and experimental study of neutralization control strategy, which finally passed the engineering assessment test. Since the launch of 'Taiji-1' satellite on 31 August, 2019, the RF ion micropropulsion system has successfully completed nearly one hundred test missions in space. The test results indicate that CNTN does not have performance degradation, and the neutralization control strategy is effective.

Boosting the Electron Beam Transmittance of Field Emission Cathode Using a Self-Charging Gate

“…We selected 11 different gate-type cathodes, including the cathodes for LISA-PATHFINDER, the CNT neutralizer for the 'Taiji-1' satellite missions, and other cathodes. 4,16,41,47,48,[88][89][90][91][92][93] The comparison results demonstrate that the SiNx-gate based cathode exhibits a significantly higher transmittance. By the way, it is noteworthy that certain cathodes exhibit a greater current magnitude compared to the cathode we have designed.…”