Charle's WIlson perfected his first cloud chamber in 1911. First, the chamber was saturated with water vapor. Next, the pressure was lowered by the movement of a diaphragm, which expanded the air inside. This also cooled the air, creating conditions favorably to condensation.
When an ionizing particle passed through the chamber, water vapor condensed on the resulting ion (charged particle), and a trail of the particle became visible in the vapor cloud. For example, when an alpha particle ( a helium nucleus, which has a positive charge) moved through the cloud chamber, it tore off electrons from atoms in the gas, temporarily leaving behind charged atoms.
Water vapor tended to accumulate on such ions, leaving behind a thin band of fog reminiscent of smoke-writing airplanes. If a uniform magnetic field was applied to the cloud chamber, positively and negatively charged particles curved in opposite directions. The radius of curvature then be used to determine the momentum of the particle.
In 1952, physicist Alexander Langsdorf developed the diffusion cloud chamber, which employed colder temperatures and was sensitized for radiation detection for longer periods of time than traditional cloud chambers. In 1952, physicist Donald Glaser invented the bubble chamber. This chamber employed liquids, which are able to reveal the tracks of more energetic particles than the gasses on traditional cloud chambers. More recent spark chambers employ a grid of electric wires to monitor charged particles by the detection of sparks.
Cloud Chamber
Re: Cloud Chamber
It would be really cool to have a description of the particles and interaction in the picture. Looks like a collision in one part of it.