Study On Test System For Multiplying Electron Gain In Electron Multiplier Layer For EBAPS

With the rapid development of digital low light night vision technology,Electron Bombarded Active Pixel Sensor has become the most promising low-light pixel sensor and has become a hot research topic in the field of microscopic imaging at home and abroad,due to its high sensitivity,digitization,low noise,low power consumption,and small size.Because the performance of EBAPS is greatly affected by the gain characteristics of the electron multiplier layer,however,there is no effective evaluation method in China that can be used to measure the electron multiplication layer in EBAPS.This paper focuses on the electron multiplication layer gain test technique EBAPS expand the preliminary study,the pulse electron source,front-end electronics system,and back-end data acquisition system required for electron multiplication layer gain test system in EBAPS are studied.This paper first analyzes the gain principle of electron multiplication layer in EBAPS,and designs the test system scheme for this gain characteristic.The test system mainly includes four parts:vacuum system,pulse electron source,front-end electronics and data acquisition.The pulsed electron source provides a stable pulsed electron beam for the test system,mainly including filament,filament power supply,grid,acceleration high voltage power supply,pulse bias power supply.For front-end electronics,this paper first performs theoretical analysis and circuit simulation of a charge-sensitive amplifier circuit.Secondly,design and simulation of the pole-zero cancellation circuit and Gaussian shaping circuit of the signal conditioning circuit are carried out.In data acquisition,a back-end data acquisition system based on FPGA with peak hold function was designed to achieve fast and narrow pulse data acquisition.Subsequently,the performance tests of the charge-sensitive amplifier circuit and pulsed electron source were performed in this paper.The test results show that the designed charge-sensitive amplifier circuit and pulsed electron source meet the basic requirements of the test system.Finally,we set up EBAPS electron multiplication layer test platform,and65?m layer of electron multiplication gain test conducted experiments.The results show that as the incident energy increases,the gain of the electron multiplying layer also increases,the charge collection efficiency of the electron multiplying layer with a doping concentration of10¹⁵ particles/cm³ and a substrate thickness of 65?m was 3.6%,basically consistent with the previous simulation results.It is verified that the entire system satisfies the design requirements and this system can provide technical support for the preparation of high-performance EBAPS electron multiplier layers in the future.