Optimization Design And Simulation Research Of The Particle Energy Analyzer With Small Deflection Angle

The energy analyzer is an instrument widely used in space exploration.Usually,the energy analyzer uses electrostatic field to screen ions to detect the energy of particles.Through the simulation study of the working principle of the energy analyzer and discussing the influencing factors of the analyzer working process,the structure is further optimized and the working performance is improved.In this paper,combined with theoretical analysis and the use of multiphysics simulation software COMSOL Multiphysics5.3,a small declination particle energy analyzer has been simulated and optimized.The main work includes:1)Based on the theory of ion motion in electrostatic field and the theory of low-energy ion collision,the theoretical basis of simulation of the particle energy analyzer with small deflection angle has been established.2)The three-dimensional simulation models of collimation and ionization regions of the analyzer have been established.In the simulation of collimation zone,the influence of the length and width of the filter plate on the electric field distribution have been analyzed.The influence of pressure,voltage,length and width of the plate,distance between the plate and the entrance,and space charge particle type on the filter effect have been analyzed.In the simulation process of ionization zone,the distribution characteristics of electric field in the ionization zone and the influence of electric field on the ion trajectory of neutral particles after ionization have been calculated,and the collision process between electrons and neutral particles has been calculated.3)Two-dimensional and three-dimensional simulation models of the deflection region of the analyzer have been established.In the two-dimensional simulation,the electric field distribution,ion trajectory and the energy spectrum have been calculated,and the energy resolution and plate factor of the analyzer based on the energy spectrum has been calculated.In the three-dimensional simulation,the electric field distribution and ion transport rate have been calculated.At the same time,the voltage of microchannel plate(MCP)has been optimized.It has been found that the effect is better when the MCP voltage is-100 V.The structural parameters of the deflection zone have been optimized,and the energy spectra of the three-dimensional simulation before and afteroptimization and the two-dimensional simulation have been compared.The results have shown that the optimized three-dimensional simulation model has higher ion transmission efficiency and better energy resolution.Under the optimized size of three-dimensional simulation model,the angle of ion incidence,temperature and pressure parameters have been simulated and analyzed.The results have show that:The analyzer has angular resolution only in one direction.When the gas pressure is less than 0.01 Pa,the influence of residual neutral gas can be neglected.The change of temperature will affect the ion passing rate,but has no effect on the energy resolution.The simulation method provides theoretical and simulation support for the design and manufacture of the small deflection angle particle energy analyzer.Meanwhile,the calculation results provide an important reference for the selection and optimization of the structural parameters of the small declination particle energy analyzer.