A scanning electron microscope (SEM) is a microscope that uses a beam of electrons rather than visible light to produce images of specimens. Description of the Operation of an SEM Electrons arc accelerated from the electron gun to the anode. The electric - Electron gun potential difference between the electron gun and the anode accelerates the electrons to a speed of 2.65 x 10' m/s. Electron . O bean After this acceleration, the electrons - Anude pass through an opening in the anodc and enter the magnetic lens. The magnetic lens focuses the beam of electrons. A particular electron - Magnetic lens experiences a magnetic force of 3.31 x 10-12 N while in the magnetic lens. As a result of this magnetic force, To image processor the path of the electrons spirals and the beam of clectrons becomes focused. Scanning coils deflect the beam of Scanning coils electrons back and forth across the specimen. Some electrons from the beam reflect off the specimen at the same speed at which they hit. The backscattered Backscattered electron electron detector picks up these Secondary detector electron electrons. These backscattered detector electrons provide information about the composition and surface characteristics of the specimen. The electron beam causes the specimen to emit electrons from its surface. The Stage Specimen secondary electron detector picks up these electrons. Information collected from the scanning coils and the two detectors is sent to the image processor. This processor produces a three-dimensional image of the specimen. 2. The instantaneous radius of the resulting spiral of the electron's path in the magnetic lens is Ise the next page for work**