Journal of Astronautics ›› 2019, Vol. 40 ›› Issue (11): 1375-1382.doi: 10.3873/j.issn.1000-1328.2019.11.014

Previous Articles    

Hot Gap Change Simulation for Triple Grid of a 30 cm Diameter Ion Thruster under Space Environment

SUN Ming ming, GENG Hai, WANG Liang, ZHENG Yi   

  1. Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou 730000, China
  • Received:2018-12-24 Revised:2019-03-29 Online:2019-11-15 Published:2019-11-25

Abstract: The finite element method (FEM) and ground thermal equilibrium test verification are used to simulate the thermal displacement of the triple grid in on-orbit working condition without and with active thermal control equipment, and the breakdown risk is evaluated under the current start-up process of the ion thruster. The results show that the thermal deformation directions of the three grids are all normal direction, and the minimal spacing position is in the central area of the triple grid. The largest hot gap between the screen grid and the accelerator grid is 0.14 mm, and the accelerator grid and the decelerator grid are fitted when the thruster is operating at 5kW work mode under -269 ℃ low temperature conditions on orbit. The lowest initial temperature of the triple grid is -102 ℃ under the influence of the solar radiation and steady temperature of the satellite panel. The initial temperature of the grids are -25 ℃ when the temperature of the control point reaches up to 20 ℃. Meanwhile, the minimal hot gap of the screen grid and the accelerator grid, the accelerator grid and the decelerator grid are 0.25 mm and 0.20 mm after working for 8000 s, respectively. When the temperature of the control point reaches up to 50 ℃, the minimal hot gap between the three grids are 0.31 mm and 0.30 mm then after working for 9000 s, respectively, which is able to meet the requirement of 0.25 mm safe breakdown spacing.

Key words: Ion thruster, Triple grids, Space environment, Hot gap change

CLC Number: