一级束流光学设计不仅要确定传输系统的总体结构,而且也会影响到系统各阶像差初始值的大小。所以在高级设计之前,有较小初始像差值的一级设计显得十分必要。本文采用罚函数法,能有效地实现这一要求。各阶像差系数和束流元件磁场各阶分量的关系式 The first-order beam optics design not only determines the overall structure of the transmission system, but also the magnitude of the initial values ​​of the system’s aberrations. So before the advanced design, a smaller initial aberration value of the first-level design is very necessary. This paper uses the penalty function method, which can effectively achieve this requirement. The relationship between the aberration coefficient of each order and each component of the magnetic field of the beam element