intermediate lens

The "intermediate lens" is placed between the objective lens and the projector lens. The intermediate lens works in the following way. The intermediate lens changes focusing position either on a diffraction pattern or a TEM image produced by the objective lens by adjusting its excitation, and forms the magnified pattern or image on the object plane of the projector lens. Normally, the intermediate lens consists of three parts: The first part mainly selects focusing position, the second part magnifies the focused pattern or image, and the third part mainly achieves rotation-free condition. The magnification of the intermediate lens is varied from ～0.5× to ～100×. When the total magnification is 100×, the magnifications for the first, second and third parts are 4× to 5×, ～10×, and 2× to 3×, respectively.

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