Design Of Hardware And Software For Measurement And Control System Of Secondary Electron Emission Coefficient

Secondary electron emission is a very abundant area of research.Because the secondary electron emission are not only important factors in determining the reliability,safety and working lifecycle of the spacecraft,but also have an important impact on the performance of the vacuum electronic devices.Therefore,how to measure the secondary electron emission coefficient accurately and quickly is of great significance to the evaluation,design,performance inspection and improvement of Spacecraft Surface Material and many vacuum electronic devices.The measurement of the secondary electron emission coefficient is mainly divided into two categories: one is the measurement of the secondary electron emission of metal materials.Because of its good conductivity,it is relatively easier to measure compared to the other one which is the measurement of the insulator material’s,for the simple reason that insulator material has a very poor conductivity and its mechanisms of secondary electron emission phenomenon is much more complicated.At present,there is no perfect solution for how to accurately measure the secondary electron emission coefficient of insulator materials under the bombardment of different high negative voltage electrons.In view of this,this paper creatively proposed a new method of measuring the secondary electron emission coefficient of the insulator,which can realize the accurate measurement of the secondary electron emission coefficient of the insulator.Secondary development of an Acquisition card system is made and a software is designed which can effectively and automatically measure and analyze in real time the secondary electron emission coefficient of target materials under the bombardment of different high negative voltage electrons and display the relevant data through the graphical interface to eliminate the shortcoming that secondary electron emission coefficient can not be measured quickly.The correctness of the measuring system designing is verified by the rapidly automatic data acquisition of the software,and the relationship between k and electron beam current,collector electrode voltage and gate voltage of the electron gun are investigated.Finally,datas were measured with the glass plate as target material and the experimental datas were fitted according to the theoretical formula,and the relationship between the secondary electron emission coefficient δ and the negative volt v was obtained.In conclusion,this paper reseaches the secondary electron emission coefficient acquisition scheme and its feasibility evaluation.Collection method of secondary electrons,charge removal technology of the surface of the insulating material,and the measurement technology of the weak pulse current signal are intensively studied.At the same time,a real-time acquisition software application is developed to establish a fast and accurate measurement system for the study of secondary electron emission coefficient of materials.Finally,the precise measurement of the secondary emission of the insulating material is realized which provides a scientific evaluation for the coefficient reseach.