Consider compton scattering with visible light. a photon with wavelength 500 nm scatters backward(theta=180 degree)from a free electron initially at rest .what is the fractional shift in wavelength \delta \lambda /\lambda, for the photon?

Explanation:

The Compton Shift effect consists in the increasing of the wavelength of a photon when it collide with a free electron and then is scattered and loses part of its energy.

This shift is given by the following equation:  

(1)  

Where:  

is the wavelength of the scattered photon

is the wavelength of the incident photon

is a constant whose value is given by , being the Planck constant, the mass of the electron and the speed of light in vacuum.  

the angle between incident phhoton and the scatered photon.  

Hence:

(2)  

(3) This is the shift in wavelength