Compton in 1922, explained this effect perfectly on the basis of quantum theory of radiation, which states that the radiation consists of small energy particles or packets called as photons. Energies of a photon at 500 keV and an electron after Compton scattering.It is possible to explain the Compton effect by using the wave theory of radiation, which states that the electromagnetic wave incident on the scatter should produce in it a secondary wave of the same wavelength. The wavelength change in such scattering depends only upon the angle of scattering for a given target particle.Ĭross section of compton scattering of photons by atomic electrons. The formula gives the probability of scattering a photon into the solid angle element dΩ = 2π sin Θ dΘ when the incident energy is E 0.
#Compton effect free
The Klein-Nishina formula describes the angular distribution of photons scattered from a single free electron: where ε = E 0/m ec 2 and r 0 is the “classical radius of the electron” equal to about 2.8 x 10 -13 cm. The probability of Compton scattering per one interaction with an atom increases linearly with atomic number Z because it depends on the number of electrons available for scattering in the target atom.
The maximum change in wavelength can be derived from the Compton formula: The quantity h/m ec is known as the Compton wavelength of the electron and is equal to 2.43×10 −12 m. In this case, the photon transfers to the electron as much momentum as possible. The maximum change in wavelength ( λ′ − λ) for the photon occurs when Θ = 180° (cos(Θ)=-1). The minimum change in wavelength ( λ′ − λ) for the photon occurs when Θ = 0° (cos(Θ)=1) and is at least zero. The shift of the wavelength increased with scattering angle according to the Compton formula: where λ is the initial wavelength of photon λ’ is the wavelength after scattering, h is the Planck constant = 6.626 x 10 -34 J.s m e is the electron rest mass (0.511 MeV) c is the speed of light Θ is the scattering angle. As a result of momentum conservation law, the photon must lower its momentum given by: So the decrease in photon’s momentum must be translated into a decrease in frequency (increase in wavelength Δ λ = λ’ – λ). While the electron gains momentum (mass x velocity), the photon cannot lower its velocity.
The photon bounces off the electron upon collision, giving up some of its initial energy (given by Planck’s formula E=hf). In the case of Compton scattering, the photon of frequency f collides with an electron at rest. Compton scattering formula is the mathematical relationship between the shift in wavelength and the scattering angle of the X-rays. Compton explained that the particle-like momentum of photons causes the X-ray shift. The Compton formula was published in 1923 in the Physical Review. The energy transferred to the recoil electron can vary from zero to a large fraction of the incident gamma-ray energy.Photons undergo a wavelength shift called the Compton shift.It is the scattering of photons by atomic electrons.Compton scattering dominates at intermediate energies.Key characteristics of Compton Scattering
Compton earned the Nobel Prize in Physics in 1927 for this new understanding of the particle nature of photons. H.Compton observed the Compton scattering in 1923 at Washington University in St. The energy transferred to the recoil electron can vary from zero to a large fraction of the incident gamma-ray energy because all scattering angles are possible. The photon transfers a portion of its energy to the recoil electron. This deflection decreases the photon’s frequency’s energy (decrease in photon’s frequency) and is called the Compton effect. In Compton scattering, the incident gamma-ray photon is deflected through an angle Θ with respect to its original direction. This deflection decreases the photon’s frequency’s energy (decrease in photon’s frequency) and is called the Compton effect.Ĭompton scattering is the inelastic or nonclassical scattering of a photon (which may be an X-ray or gamma-ray photon) by a charged particle, usually an electron. The shift of the wavelength increased with scattering angle according to the Compton formula. Compton scattering is the inelastic or nonclassical scattering of a photon (which may be an X-ray or gamma-ray photon) by a charged particle, usually an electron.
0 kommentar(er)
