This experiment utilizes a highly evacuated electron diffraction tube to study the wave-like properties of electrons. The electrons are emitted by the thermionic emission and accelerated towards target by applying a very high potential (2000-5000 V). The target is a micro meshed nickel grid on which a thin layer of graphite is deposited. The electrons being diffracted through the graphite satisfy the Bragg's condition and produce an interference pattern consisting of two rings. To measure the diameter of the ring, digital photographs are taken of the screen and analysis is done using a freely available software ImageJ. This experiment familiarize our students with digital photography and they will learn about its implications in experimental physics.
|Sample Results||A graph for the diameter of the rings versus accelerating voltage to find the inter-planar spacing|
|Version||29 September 2015, 2015-v2|
Further Readings and References
- Electron diffraction tube User manual for electron diffraction tube (3B Scientific)
- Physics Physics, John Willey & Sons, Inc. , David Halliday, Robert Resnick and Kenneth S. Krane 993 , (1992).
- Modern Physics Modern Physics, Thomson learning , Raymond A. Serway, Clement J. Moses, and Curt A. Moyer 152 , (2005).