Analysis of application range of simplified models for field to thermo-field to thermionic emission processes from the cathode

作     者：Li SUN Zhuo DAI Ming XU Wei WANG Zengyao LI 孙丽;代卓;徐鸣;王伟;李增耀

作者机构：Applied Physics DepartmentXi’an University of TechnologyXi’an 710048People’s Republic of China Key Laboratory of Thermo-Fluid Science and EngineeringMinistry of EducationSchool of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049People’s Republic of China 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2024年第26卷第9期

页      面：51-60页

核心收录：

学科分类：07[理学] 070202[理学-粒子物理与原子核物理] 0702[理学-物理学] 

基　　金：supported in part by National Natural Science Foundation of China(Nos.52176087 and 52277164) Foundation for Innovative Research Groups of National Natural Science Foundation of China(No.51721004) Scientific Research Program Funded by Shaanxi Provincial Education Department(No.23JP115) Youth Innovation Team of Shaanxi Universities,in part by the Natural Science Basic Research Plan of Shaanxi Province(Nos.2021J Z-48 and 2020JM-462) 

主　　题：electron emission processes application range Murphy-Good theory implicit particlein-cell Monte Carlo collision method 

摘      要：Electron emission plays a dominant role in plasma-cathode interactions and is a key factor in many plasma phenomena and industrial *** is necessary to illustrate the various electron emission mechanisms and the corresponding applicable description models to evaluate their impacts on discharge *** this study,detailed expressions of the simplified formulas valid for field emission to thermo-field emission to thermionic emission typically used in the numerical simulation are proposed,and the corresponding application ranges are determined in the framework of the Murphy-Good theory,which is commonly regarded as the general model and to be accurate in the full range of conditions of the validity of the *** parameterization was used to evaluate the emission current density of the Murphy-Good formula,and a deviation factor was defined to obtain the application ranges for different work functions(2.5‒5 eV),cathode temperatures(300‒6000 K),and emitted electric fields(10^(5) to 10^(10) V·m^(-1)).The deviation factor was shown to be a nonmonotonic function of the three parameters.A comparative study of particle number densities in atmospheric gas discharge with a tungsten cathode was performed based on the one-dimensional implicit particle-in-cell(PIC)with the Monte Carlo collision(MCC)method according to the aforementioned application *** was found that small differences in emission current density can lead to variations in the distributions of particle number density due to changes in the collisional *** study provides a theoretical basis for selecting emission models for subsequent numerical simulations.