Find+some+history+about+SEM

__The SEM was pioneered by__ [|Manfred von Ardenne] __in the 1930s. The instrument was further developed by__ [|Charles Oatley] __and first commercialized by Cambridge Instruments. The development of the Scanning Electron Microscope in the early 1950's brought with it new areas of study in the medical and physical sciences because it allowed examination of a great variety of specimens. As in any microscope the main objective is for magnification and focus for clarity. An optical microscope uses lenses to bend the light waves and the lenses are adjusted for focus. In the SEM, electromagnets are used to bend an electron beam which is used to produce the image on a screen. By using electromagnets an observer can have more control in how much magnification he/she obtains. The electron beam also provides greater clarity in the image produced.

The first modern scanning electron microscope, constructed by D. McMullan in the__ __Cambridge University Engineering Laboratory in 1951. Source: Electron Optics and Electron Microscopy, P.W. Hawkes.__