On abnormal behaviors of ion beam extracted from electron cyclotron resonance ion thruster driven by rod antenna in cross magnetic field  

作　　者：Juan LI Shenghui FU Yurou YANG Zhenfeng DING 李娟;付省辉;杨雨柔;丁振峰(School of Physics,Dalian University of Technology,Dalian 116024,People's Republic of China)

机构地区：[1]School of Physics,Dalian University of Technology,Dalian 116024,People's Republic of China

出　　处：《Plasma Science and Technology》2021年第8期150-160,共11页等离子体科学和技术（英文版）

基　　金：supported by National Natural Science Foundation of China(No.11975070);Open Funds for Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics(No.zwk1609)。

摘　　要：In a 2.45 GHz electron cyclotron resonance(ECR)ion thruster powered with rod antenna under a cross magnetic field,abnormal behaviours such as sudden drop of ion beam current(Ib)and larger increasing-rate of Ibin the high microwave power(Pw)discharges at high gas flow rates were observed.A differential method was proposed to reveal the changes in the radial profiles of gray values extracted from the end-view discharge images.The increasing-rate of Ibwith respect to Pwwas used to evaluate efficiencies of ion production and transport.Analyses indicate that discharges are dominantly sustained by ordinary wave via electron heating in the electron plasma resonance layer that can shift along the rod-antenna,and extraordinary wave can only ignite a discharge in the ECR layer in the low gas flow rate regime.In terms of the confinement region defined by the magnetic field lines intercepting with the screen grid,the confinement region of the optimized 2.45 GHz cross magnetic field takes the shape of hourglass,enabling the high increasing-rate of Ib with respect to Pw in high power discharges at high gas flow rates.Correlated with the accompanied bright boundary layer appearing in the differentiated image,the sudden drop of Ib in the low gas flow rate regime is attributed to the discharge ignited by the enhanced extraordinary wave in the ECR layer neighbouring the narrowest confinement region,where the produced ions can promptly enter the loss region.

关 键 词：ECR ion thruster ion beam current discharge mode transition 

分 类 号：V439.1[航空宇航科学与技术—航空宇航推进理论与工程]