轴对称静电场电位导数计算的数值方法探究

Research on the Numerical Methods for Calculating the Derivatives of Electropotential of an Axisymmetrical Electrostatic Field

本文讨论了轴对称的静电阴极透镜系统轴上电位导致计算的数值方法。比较了“中心差分”公式和“五点差分”公式得到的结果，提出以“五点差分”公式代替“中心差分公式来计算轴上电位导数。

In this paper have discussed the numerical methods for calculating the deriveatives of elec-tropotential at the axis of an axisymmetrical elecctrostatic cathode lens System. The result obtained byuse the centre difference formular has compared with that by use the five points formular. Then the pa-per has proposed to replace te centre difference formular with the five points difference formular.