Compton Scattering


From physick.wikispaces.com (Connor Boggs)


Arthur Compton observed Compton scattering in 1923, and was awarded the Nobel Prize in Physics in 1927.
Arthur Compton observed Compton scattering in 1923, and was awarded the Nobel Prize in Physics in 1927.





Compton Scattering


Compton scattering occurs when an incident X-Ray photon hits an electron, and is scattered at a different angle through an alternate path.
This is an example of Compton Scattering
This is an example of Compton Scattering
The incident and scattered photons also have different wavelengths, as there is a loss of energy from the incident photon to the scattered photon,
which results in the scattered photon having a larger wavelength. This is known as the Compton Effect.




Importance:


The importance of this discovery lies within the Law of Conservation of Momentum and the Law of Conservation of energy. Because both energy and momentum must both be conserved, the scattering must result in the electron being given some of the energy, causing it to move, and the photon to be emitted in a different direction. This discovery was paramount in describing light as not only acting as a wave, but also as a stream of particles.




Formula:


Using many of Einstein's theories, Compton was able to find a formula that could be used to find the change of wavelength from the incident photon to the scattered photon.
The formula he created is as follows:

external image ComptonFormula.gif


Where:
external image e05a30d96800384dd38b22851322a6b5.png = Initial wavelength
external image 805faa8c47be48cbc87dcdfe0f03656d.png = Scattered photon's wavelength
external image 2510c39011c5be704182423e3a695e91.png = Plank's Constant
external image 4a4bb6afaa48dfd8533bdac7f66dd9d5.png = Mass of electron
external image 4a8a08f09d37b73795649038408b5f33.png = Speed of light
external image 50d91f80cbb8feda1d10e167107ad1ff.png = Scattering angle of scattered photon

Applet:


http://www.kcvs.ca/site/projects/physics_files/compton-scattering/compton-scattering.swf

Reference

  1. http://www.ndt-ed.org/EducationResources/CommunityCollege/Radiography/Physics/comptonscattering.htm
    http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/comptint.html
    http://www.kcvs.ca/site/projects/physics.html