How does Thomson scattering work?

Published by Charlie Davidson on

How does Thomson scattering work?

Thomson scattering is the scattering of photons by free electrons in an ionized gas. Since the number density of scattered photons and their spectral distribution is directly related to important plasma properties such as ne and Te, it is one of the most prominent techniques in plasma diagnostics.

What is the Thomson scattering cross section?

Light scattering from free electrons is described by Thomson scattering in the low-energy limit, with a cross-section of 8 π / 3 e 2 / 4 π ε 0 m c 2 2 , and by Compton scattering in the relativistic limit. Stimulated Thomson or Compton scattering is the source of light emitted from free electron lasers.

What is the difference between Thomson scattering and Compton scattering?

An electromagnetic wave impinging on a charged particle, such as an electron, creates an oscillating motion of the charge. In turn, the oscillating charge generates radiation. If the motion of the charge is nonrelativistic, the process is called Thompson scattering. The relativistic case is called Compton scattering.

Is Thomson scattering elastic?

In contrast to Compton scattering, Thomson scattering is an elastic scattering of electromagnetic radiation by a free moving charged particle.

What is another name for Thomson scattering?

Compton scattering
The scattering of a photon by a charged particle is called Compton scattering, and the quantum mechanical version of the Compton scattering cross-section is known as the Klein-Nishina cross-section.

What is the another name for Thomson scattering?

photon scattering cross section is called the Thomson cross section, symbolized by the Greek letter sigma with subscript zero, σ0, and is equal to a numerical factor times the square of the term, electric charge squared divided by electron rest energy, or σ0 = (8π/3) (e2/mc2)2.

What is the difference between elastic and inelastic scattering?

Elastic scattering occurs when there is no loss of energy of the incident primary electron. Elastically scattered electrons can change direction but do not change their wavelength. Inelastic scattering occurs when there is an interaction that causes loss of energy of the incident primary electron.

Who discovered Thomson scattering?

J. J. Thomson

Sir J. J. Thomson OM PRS
Born Joseph John Thomson18 December 1856 Cheetham Hill, Manchester, England
Died 30 August 1940 (aged 83) Cambridge, England
Citizenship British
Nationality English

Why is Thomson scattering important in plasma physics?

Thomson scattering is an important phenomenon in plasma physics and was first explained by the physicist J. J. Thomson. As long as the motion of the particle is non- relativistic (i.e. its speed is much less than the speed of light), the main cause of the acceleration of the particle will be due to the electric field component of the incident wave.

How is Thomson scattering related to Compton scattering?

Thomson scattering is the elastic scattering of electromagnetic radiation by a free charged particle, as described by classical electromagnetism. It is just the low-energy limit of Compton scattering: the particle kinetic energy and photon frequency do not change as a result of the scattering.

How is Thomson scattering related to low energy limit?

In the low-energy limit, the electric field of the incident wave (photon) accelerates the charged particle, causing it, in turn, to emit radiation at the same frequency as the incident wave, and thus the wave is scattered. Thomson scattering is an important phenomenon in plasma physics and was first explained by the physicist J. J. Thomson.

Is the cosmic microwave background a result of Thomson scattering?

The cosmic microwave background contains a small linearly-polarized component attributed to Thomson scattering. That polarized component mapping out the so-called E-modes was first detected by DASI in 2002. The solar K-corona is the result of the Thomson scattering of solar radiation from solar coronal electrons.

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