The electron microscope is a device used to view objects with respect to a high magnification and resolution that uses electron beams in order to display the image properly. The electron microscope was developed by two scientists; A German engineer, Max Knoll (1897-1969) and a Physicist Ernst Ruska (1906-1988) in the year 1931. Ernst Ruska was awarded the noble prize for his work in the electron optics in the year 1986. In 1935, Max Knoll built the first scanning electron microscope.
The electron microscopes consist of two main types. These microscopes include the transmission electron microscope and the scanning electron microscope.
The transmission electron microscope was the first electron microscope to be developed in 1931. The transmission…show more content… Components of the scanning electron microscope include the condenser lens, objective lens and the electromagnetic coils. The condenser lens are responsible for focusing the electron beam to the objective lens while the objective lens is responsible for the size of the electron beam impinging the surface on the sample surface. The electromagnetic coils is essential for the driving the raster scanning by deflecting the electron beam. The image produced in the scanning electron microscope are detected by the secondary electrons which are emitted from the surface as a result of excitation by the primary electron beam. As compared to the transmission electron microscope, the scanning electron microscope also has a powerful electron gun that shoots electron beams down towards the specimen. The scanning electron microscope has a series of electromagnetic coils that pull back and forth in order to scan the specimen’s surface. There are several steps to how a scanning electron microscope works. Some of these steps include: firstly, the electrons are fired into the machine. In the machine there is an important part where objects are scanned within a tight sealed vacuum chamber since specific electrons beams cannot travel successfully through air. A node then attracts the electrons and moves them into an energetic beam. Secondly, an electromagnetic