一种返回电子式的月表电场探测技术  

Return-type Electron-based Lunar Surface Electric Field Detection Technology

作　　者：金菲凡 刘超 张贤国[1,3,4] 张爱兵 王文静[1,3] JIN Feifan;LIU Chao;ZHANG Xianguo;ZHANG Aibing;WANG Wenjing(National Space Science Center,Chinese Academy of Sciences,Beijing 100190;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049;Beijing Key Laboratory of Space Environment Exploration,Beijing 100190;Key Laboratory of Science and Technology on Space Environment Situational Awareness,Chinese Academy of Sciences,Beijing 100190)

机构地区：[1]中国科学院国家空间科学中心,北京100190 [2]中国科学院大学天文与空间科学学院,北京100049 [3]天基空间环境探测北京市重点实验室,北京100190 [4]中国科学院空间环境态势感知技术重点实验室,北京100190

出　　处：《空间科学学报》2024年第6期1106-1119,共14页Chinese Journal of Space Science

基　　金：深空探测全国重点实验室项目资助(NKLDSE2023A010)。

摘　　要：提出了一种原位探测月表电场的新技术及相应计算方法,以满足探测南极月面电场环境特性的需求.根据仿真结果,月表电场精细测量需要低能散、高电流的平行电子束发射能力,设计的低能层流电子枪在10^(–8)~10^(–5) A的发射电流下,能散<0.4 eV,且随发射电流减弱而降低;通过控制发射电流、调整阳极孔径,可对电流进行调控;采用pierce电子枪的阴阳极结构和静电透镜对电子束的平行度进行进一步控制,仿真显示10^(–7) A电子束的扩散效果较弱,各方面性能符合探测需求.此外,构建通过电子束返回时间测量垂直电场的探测方式,模拟验证月表光照区向上发射电子束时相应的电场计算结果可反映背景电场,返回电子式月表电场探测技术达到了执行月表电场测量所需的要求.This study aims to propose an active,on-site,high-resolution lunar surface electric field de-tection technology along with corresponding computational methods,to meet the requirements of explor-ing the comprehensive characteristics of the lunar surface environment,and helps understanding the in-teraction between the Moon and solar wind.According to the simulation results,precise measurement of lunar surface electric fields demands electron emission capabilities with low energy spread,relatively high current,and parallel electron beams.Preliminary system parameters with the capability of receiving re-turn current signals have been designed,including system parameters for voltage stabilization,pulse power supply modules,and signal acquisition modules.Referring to the simulation results,the low-ener-gy laminar flow electron gun designed in this study exhibits an energy spread of<0.4 eV at emission cur-rents ranging from 10^(–8) to 10^(–5) A,with the energy spread decreasing as the emission current weakens.Control of emission current is achieved by regulating the initial current of the thermionic cathode,em-ploying a cathode-anode structure like Pierce electron gun and adjusting the anode aperture.Additional control over beam parallelism is achieved using an electrostatic lens.Simulation verifies that the 10^(–7) A electron beam exhibits minimal diffusion within a 4 m working distance,meeting the requirements for ac-curate detection of lunar surface electric fields.The paper proposes and simulates the measurement of lu-nar electric fields by emitting electron beams upwards in the lunar illuminated region.The simulation and calculation results of lunar vertical electric fields show a linear relationship,verifying the feasibility of the detection plan,with the influence of background magnetic fields being negligible.The feasibility of actively adjusting the electron gun reference potential to expand the electron beam range to(–100,+100)V has also been proposed and verified.According to simulation analysis,our r

关 键 词：月表电场 月球南极 表面充电 低能电子束 电子枪 数值仿真 

分 类 号：V447[航空宇航科学与技术—飞行器设计]