Compton effect and compton scattering, Physics

Q. Explain how Compton scattering confirms the quantum nature of radiation.

OR

What is "Compton Effect"? Deduce an expression for shift in wavelength of scattered X rays by Compton Scattering.

Ans.

In 1921, A. H. Compton discovered that when a monochromatic beam of high frequency radiation scattered by substance, the scattered radiation contains two components.

 

(i)     Unmodified Radiation - The radiation of unchanged frequency in scattered beam as incident beam.

(ii)    Modified Radiation - The radiation having lower frequency or greater wavelength then incident radiation. This phenomenon is known as Compton effect.

Theory - According to quantum theory, primary x rays beam is made up of photons of energy hv, where v is the frequency of the primary x rays. These photons travel with speed of light C and  possess momentum given by hv/c and also obey all the laws of conservation of energy and momentum when these photons strike the electrons of a scattering substance. The phenomenon of scattering is due to an elastic collision between the photon and the electron.

When the photon of energy hv collides with the electron of the scattered at rest, it transfers some energy to the electron i.e., it lessees energy. The scattered photon will therefore have a smaller energy than hv and consequently a lower frequency then the primary x ray. The observed change in frequency or wavelength of the scattering radiation is known as Compton effect.

In scattering process, the electron gains kinetic \energy and thus recoil with velocity v. as the work function of substance is negligibly small as compared to the energy of photon, the recoil electron is treated practically free,. Thus, during the collision, photon gives a fraction of its energy to the free electron and its relativistic mass is considered after collision.

Let a photon of energy hv collides with a free electron and after collision scattered photon of energy hv' is found at the scattering angle q while recoil electron is found at the recoil angle f as shown in Fig.

(i)            Energy Conservation Law - it states that before collision and after collision energy should remain same i.e. constant.

(ii)       Momentum Conservation Law - It states that before collision and after collision momentum should be same i.e. constant. Since momentum is a vector quantity taking component of momentum in horizontal and perpendicular direction

Posted Date: 7/11/2012 3:02:13 AM | Location : United States







Related Discussions:- Compton effect and compton scattering, Assignment Help, Ask Question on Compton effect and compton scattering, Get Answer, Expert's Help, Compton effect and compton scattering Discussions

Write discussion on Compton effect and compton scattering
Your posts are moderated
Related Questions
There are two major differences between "center of gravity" and "center of mass": 1) The term "center of gravity" aplies to the bodies with mass and weight, while the term "cent

It is the electric dipole moment induced in a system, such as an atom or molecule, by an electric field of unit strength.

On the way to school, Jamal realizes that he left his physics homework at house. His car was initially heading north at 24.0 m/s. It takes him 35.5 s to turn his car around and hea

Electric Current: Electric current may be described as the rate of flow of charge. I=q/T Where, I = electric current q = charge T = time The unit of current i

Q. Define Tangent law? A magnetic needle suspended at a point wherever there are two crossed fields at right angles to each other will come to rest in the direction of the res

Q. Orbital Velocity for Low Earth Orbit Neglecting air friction an object will sustain a low altitude orbit when the centrifugal force due to its motion in a circular orbit is

The number of independent directions in which a system (or gas molecule) can have motion, are called as the number of degrees of freedom of that molecule or object. The number of d

I need help with a problem. Must find the entropy S(E) in the microcanonical ensemble for this system for this system in terms of E and L(and the constants c,k,h(naught) and the

In an expression ½kx2 for the potential energy accumulates in the spring what does the x represent?         Answer: Quite frequently we consider there to be an object at

Illustrates the formula of Rayleigh-jeans law? RAYLEIGH-JEANS LAW The energy distribution into the thermal spectrum is specified by given formula as follows: E λ = 8Πk