What is thompson scatter?

Thompson scatter, also known as classical scatter or Rayleigh scatter, is a type of scattering phenomenon that occurs when electromagnetic radiation (such as light or x-rays) interacts with free charged particles (such as electrons). The scattering is elastic, meaning that there is no energy loss during the interaction, and the scattered photons have the same energy and frequency as the incident photons.

Thompson scatter is named after British physicist Joseph John Thompson, who first described the phenomenon in 1901. It is most commonly observed in gases, such as the Earth's atmosphere, where the density of free charged particles is relatively low.

Thompson scatter plays an important role in various scientific fields, including astronomy, where it can be used to study the properties of interstellar and intergalactic gas, and in medical imaging, where it can be used to produce high-resolution images of biological tissues.