Design Of A Technique And Experimental System For Establishing Detector Reference Potential In Space Plasma Environment

Space plasma environment affects spacecraft orbit,attitude and scientific payloads on spacecraft.Space plasma environment will affect the performance,service life and reliability of various aerospace electronic equipments.Spacecraft,according to the tasks performed,will experience different plasma environments.The detection of space plasma is of great significance not only to the study of space environment and space physics,but also to the study of spacecraft charging and discharging phenomena.It plays an important and positive role in spacecraft protection design and detector design.Space plasma can respond to a variety of space weather events quickly,such as spatial magnetic storms and substorms.In addition,there is a coupling mechanism between space plasma and volcanoes and earthquakes.Therefore,it is important to realize the detection of low-energy charged particles such as space plasma.Spacecraft is operating in plasma areas,it would interact with plasma and causes the surface to charge.The surface charging of the spacecraft will cause a certain potential difference between the spacecraft and plasma.The existence of this potential difference will affect the working condition of the scientific payload on the spacecraft to detect low-energy charged particles and affect the detection results.One of the problems faced by in-situ detection of low-energy charged particles is that it is difficult to maintain the potential of the detector close to the space plasma.Because of the difference between the potential of spacecraft's structure ground and that of surrounding plasma,and the influence of space environment characteristics,spacecraft's illumination conditions and the level of geomagnetic activity,the voltage varies greatly and is unstable.It makes detectors hard to work in a space plasma environment.Based on theoretical research,software simulation and circuit experiment,this paper presents a technique to establish a reference potential of detector.This technique can establish a stable reference potential close to the plasma potential around the spacecraft in the space plasma environment,and make the low-energy particle detector have better performance.Firstly,the plasma environment in solar-terrestrial space is introduced,and the space plasma environment in which the spacecraft operates is briefly analyzed and introduced.Then,the charge-discharge theory of spacecraft in plasma environment is introduced,and some related examples are listed.The influence of spacecraft with potential on detector is analyzed.Based on the charged theory of isolated conductor in plasma environment,the potential of isolated conductor in space plasma environment is studied and analyzed.Then,the potential of isolated conductor relative to surrounding plasma is simulated and analyzed by using scientific software.Finally,the experimental circuit is designed,and the experimental system is designed to carry out the related testing work,which verifies the feasibility of this technology and the range of the reference potential established.This technique will be used in the Space Station Experiment Module I project to provide a reference potential for on-orbit space plasma detector.