
Electron microscopes generate images by bombarding samples with electrons and then converting the results of this interaction into visual images. In order to form an image, the generated electrons need to be tightly controlled. Electron beams come from filaments made of various materials. The most common is the tungsten hairpin gun, which is widely used in scanning electron microscopes, transmission electron microscopes, and microprobe systems. This filament is a tungsten ring that acts as a cathode. Apply voltage to the…