| 摘要 |
PURPOSE:To make it possible to judge merits and demerits of a systematic property while shortening calculation time by analytically finding a change of a lens property to an analogous change of a geometric size. CONSTITUTION:As an independent parameter, in addition to an analogous ratio (g) of a geometrical size in a form of a certain lens electrode, two of four of lens excitation (a rtio of lens impression voltage to changed particle source impression voltage), a lens magnification, a distance between the image surface and the lens, a distance between the object surface and the lens are taken for calculating potential distribution and orbit in a certain one value of (g) to find a relation of a lens property to lens excitation. Then, a lens form is optimized by calculating the lens property to a change of the value of (g) in the value specified of two independent parameters. Thereby, calculation time can be shortened to judge merits and demerits of a systematic property.
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