A cloud chamber, also known as a Wilson cloud chamber, is a particle detector used for visualizing the passage of ionizing radiation.
Fig. 2: The original cloud chamber of C.T.R. Wilson at the Cavendish Lab, Cambridge England.
Fig. 4: How condensation trails are formed in a diffusion cloud chamber.
Fig. 5: In a diffusion cloud chamber, a 5.3 MeV alpha-particle track from a Pb-210 pin source near Point (1) undergoes Rutherford scattering near Point (2), deflecting by angle theta of about 30 degrees. It scatters once again near Point (3), and finally comes to rest in the gas. The target nucleus in the chamber gas could have been a nitrogen, oxygen, carbon, or hydrogen nucleus. It received enough kinetic energy in the elastic collision to cause a short visible recoiling track near Point (2). (The scale is in centimeters.)
Example of watercooled thermoelectric cloud chamber
In experimental and applied particle physics, nuclear physics, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionizing particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator. Detectors can measure the particle energy and other attributes such as momentum, spin, charge, particle type, in addition to merely registering the presence of the particle.
Cloud chambers visualize particles by creating a supersaturated layer of vapor. Particles passing through this region create cloud tracks similar to condensation trails of planes
Recording of a bubble chamber at CERN