SEM에서 두 개의 집속 렌즈 반배율 설계

The advantage in using two lenses is that the demagnification can be varied over a wide range by variation of the power of the first lens. Most microscopes are fitted with a 2 stage condenser lens system. The first lens produces a demagnified image of the beam source. The second lens projects an image of the demagnified source on the object. In this paper, we show the demagnification design in the design procedure of 2-stage condenser lens system. we also compare the designed demagnification with the calculated demagnification by measuring lens currents through the real system.