| 摘要 |
PROBLEM TO BE SOLVED: To observe a second dimensional distribution image of a specific element in real time, by setting an exposure time of an image of an energy region not including core loss electrons shorter than an exposure time of an image of an energy region including core loss electrons. SOLUTION: Supposing that a core loss energy of a target element is Ec and a width of an energy selection slit 17 isΔE, an acceleration voltage is increased by Ec by an acceleration voltage control device 13, thereby obtaining a post edge image including core loss electrons. The acceleration voltage is then increased by Ec-ΔE, thereby obtaining a pre edge image immediately before the core loss energy. The acceleration voltage is increased by Ec-2ΔE, thereby obtaining a pre pre edge image. The pre edge image and pre pre edge image are picked up for the same exposure time by an image pick-up device 8, thereby obtaining an intensity ratio R (generally R<1). The post edge image is picked up for an exposure time tpre , the pre edge image is picked up for an exposure time tpre×R, and the images are differentially operated at a control computer 20. An element distribution image is displayed at a CRT monitor 15.
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