The Electron Diffraction Tube

The electron diffraction experiment where we sent a beam of electrons through a graphite crystal, can be viewed either as an experiment to demonstrate the wave nature of electrons or as an experiment to study the structure of a graphite crystal. Perhaps both.
The apparatus, shown in Figure (1), consists of an evacuated tube with an electron gun at one end, a graphite target in the middle, and a phosphor screen at the other end. A finely collimated electron beam can be aimed to strike an individual flake of graphite, producing a single crystal diffraction pattern on the phosphor screen. Usually you hit more than one crystal and get a multiple image on the screen, but with some adjustment you can usually obtain a single crystal image.

Figure 1: Electron diffraction apparatus. An electron beam, produced by an electron gun, strikes a graphite crystal located near the center of the evacuated tube. The original beam and the scattered electrons strike a phosphor screen located at the end of the tube.

مواضيع ذات صلة

Symmetry operations

Surface waves

Waves in solids

Shock waves

Bow waves

Coupled pendulums

Modes in two dimensions

Localized wave trains

Beat notes and modulation

Adding two waves

Waves

The failure of classical physics