Demos: 8A-10 Electron Diffraction
This demonstration illustrates the wave nature of electrons. It is possible to observe an interference pattern caused by a beam of electrons passing through a polycrystalline graphite target on a fluorescent screen (similar to light passing through a diffraction grating). Electrons emitted by a heated cathode are constrained to a narrow beam and are then focused through a micro-mesh nickel grating. The result of this diffraction is two concentric circles on the fluorescent screen. The wavelength of the electrons can be determined for various anode voltages from the radius of the circles and the distance between the crystal layers in the graphite. This demonstration confirms the de Broglie hypothesis.Last Updated: Nov 30, 2023 11:25 AM