Modern Physics > Quantum Effects > X-Ray and Electron Diffraction

DCS# 7A60.10

---

ELECTRON DIFFRACTION

---

---

APPARATUS

electron diffraction tube	202-04-D
power supply	202-04-D
video camera	202-09-C4

---

DESCRIPTION

Show diffraction patterns produced by an electron beam passing through various targets.

One can use the Bragg equation to calculate the separation between lattice planes from measurements of the pattern spacing on the screen.

 

NOTES

Set-up:

 

 

Intensity and voltage should be turned off before turning the power supply on.  Allow a few minutes for tube filament to warm up, then set anode voltage to about 6 kV but do not exceed 7 kV. Turn intensity up to about 6.5.  Current should be less the 100 uA.

 

Use horizontal and vertical controls to steer beam and locate targets.

 

The following images are taken from the Welch Scientific Company Instructions for the Electron Diffraction Tube:

two-dimensional hexagonal pyrolitic graphite	polycrystalline aluminum	polycrystalline hexagonal p-graphite