Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)
JAXA's Engineering Degital Innovation Center, Japan Aerospace Exploration Agency (JAXA)(JEDI)
Tokyo Metropolitan University : Tokyo Metropolitan College of Industrial Technology
Akashi National College of Technology
Faculty of Engineering, Gifu University
School of Systems Engineering, National Defense Academy
School of Engineering, Yokohama National University
Faculty of Science and Engineering, Doshisha University
Faculty of Life and Medical Sciences, Doshisha University
Okayama University of Science
出版者
宇宙航空研究開発機構
出版者(英)
Japan Aerospace Exploration Agency (JAXA)
雑誌名
宇宙航空研究開発機構研究開発資料
雑誌名(英)
JAXA Research and Development Memorandum
巻
JAXA-RM-11-023
ページ
1 - 77
発行年
2012-03-30
抄録(英)
For the qualification of an ion thruster system for spacecraft, a time-consuming endurance test of more than 10,000 hours is required. The cost for a lifetime qualification test of an ion thruster is hence quite high, and this situation prevents quick development and introduction of an optimal ion thruster for a specific mission. If numerical simulation can replace some of ion thruster's life tests, cost and time for the development of an ion thruster can be drastically reduced. Following this concept, a numerical tool called JIEDI (JAXA's Ion Engine Development Initiative) was developed for the lifetime evaluation of ion thruster's ion optics. To assess the lifetime of the acceleration grid of an ion thruster within affordable computational resources and computational time, the JIEDI tool treats ions and neutrals as flux tubes whose trajectories are calculated using the equations of motion for charged particles and neutrals whereas electrons are approximated as a fluid; this method, usually called the flux tube model, can drastically reduce the computational time in comparison with a full particle-in-cell (PIC) method, in which electrons are treated as particles. In this report, after describing physical model as well as numerical procedure, some numerical wear test results are reported for a single pair of carbon/carbon grid aperture of microwave ion thrusters mu10 and mu20 to evaluate the accuracy and precision of the JIEDI tool. Through comparisons with experiment, the JIEDI code showed good agreement with a real-time 18,000-hrs life test when incorporating the motion of eroded grid materials, the elastic scattering and charge-exchange collisions, the effect of secondary charged ions, and a low-energy sputtering yield model for the energy below 300 V. Numerical error caused by the uncertainty of physical model is also studied and it is found that uncertainty in beam current and plasma parameters cause 10% or less error to estimate grid hole erosion profiles. The grid erosion profile is most sensitive to the uncertainty in sticking factor, which indicates what percentage of eroded grid material arriving at a grid surface will redeposit onto the grid surface.
内容記述
形態: カラー図版あり
著者人数: 11人
内容記述(英)
Physical characteristics: Original contains color illustrations
Number of authors: 11