摘要
提出了直接积分法(DIM)研究动态电子光学成像系统时间像差的理论.以阴极面逸出的某一轴向电子初能为εz1(0≤εz1≤ε0max)的近轴电子轨迹为比较基准,给出时间像差的新定义,导出了动态电子光学成像系统时间像差系数的积分表达式.利用静电聚焦同心球系统理想模型的解析解检验了直接积分法(DIM)与τ变分法求解成像系统时间像差系数的表达式,并证明了两者的正确性与等价性.与τ变分法比较,直接积分法(DIM)给出的二级几何时间像差系数以积分形式表示,计算更简便,更适于成像系统的实际计算与设计.同时还从方法论的角度阐述了研究动态电子光学时间像差理论的体会.
A new theory for studying temporal aberrations of dynamic electron optical imaging systems by the direct integral method （DIM） is put forward. A new definition of temporal aberration is given taking a certain initial energy of electron emission emitted from the cathode surface along the axial direction εz1（0≤εz1≤ε0max） as a criterion. New expressions of the temporary aberration coefficients expressed in integral forms for the dynamic electron optical imaging system are deduced. An electrostatic concentric spherical system model is used to test and verify the expressions of temporal aberrations given by DIM and the r-variation method, the analytical solutions prove that both of the two methods are correct and equivalent. Compared to the r-variation method, DIM needs only to carry out the integral calculation for the three of temporal geometrical aberration coefficients of second order, and is therefore more convenient and suitable for computation in practical design operations. Finally, what we have learned from the study of the theory of temporal aberrations for dynamic electron optics from the point of view of methodology was elaborated,
出处
《北京理工大学学报》
EI
CAS
CSCD
北大核心
2006年第5期377-382,共6页
Transactions of Beijing Institute of Technology
基金
国家自然科学基金资助项目(60471951)
国家自然科学基金国际合作项目(60310072)
教育部高等学校博士学科点专项科研基金资助课题(20050007002)
关键词
阴极透镜
电子光学成像系统
动态电子光学
时间像差理论
cathode lenses
electron optical imaging systems
dynamic electron optics
theory of temporal aberrations
