电磁电子透镜光学参量的计算公式

用假设弱透镜焦距表达式是一个幂级数中的第一项的方法,可以导出相当准确且便于实用的电磁电子透镜物镜焦距公式。这个外推了的弱透镜近似公式能在即使相当强的激励下仍保持准确。这个方法也能用于其他一些光学参量。对于不能用此方法的光学参量,本文也导出了实用的经验公式。式中的常数是用前人发表的数据确定的。公式的准确度足够满足电子光学设计要求。

FORMULAE FOR THE OPTICAL PARAMETERS OF MAGNETIC ELECTRON LENSES

By assuming the weak lens focal length expression to be the first term in a power series, a simple and accurate formula can be derived for the objective focal length of a magnetic electron lens. This extended weak lens formula remains accurate even at strong excitations. This technique has also been applied to some of the other optical parameters. Where this approach was not practical, purely empirical formulae were derived. The constants in the for mulae were determined using data published by previous authors. The accuracies of the formulae are sufficient for most engineering design purposes.