Thomsonspredning

Thomsonspredning, also known as Thomson scattering, is a fundamental process in plasma physics and astrophysics where an electron scatters a photon, changing its direction and energy. This phenomenon was first described by J.J. Thomson in 1906 and is crucial for understanding the behavior of plasmas and the interaction of light with matter.

In Thomson scattering, an incoming photon interacts with a free electron in a plasma. The electron absorbs the photon and then re-emits it in a different direction and with a different energy. The scattered light is typically polarized and its properties can be used to infer information about the plasma, such as its electron density and temperature.

Thomson scattering is widely used in experimental and theoretical studies of plasmas. It is employed in various applications, including fusion research, where it helps in diagnosing the properties of the plasma in devices like tokamaks. Additionally, it is used in astrophysics to study the properties of interstellar and intergalactic media.

The cross-section for Thomson scattering is a fundamental constant in physics, representing the probability of the scattering event occurring. It is proportional to the square of the electron charge and inversely proportional to the fourth power of the electron mass. This makes Thomson scattering a valuable tool for both theoretical and experimental investigations in plasma physics.