- cloud chamber
-
an apparatus for determining the movements of charged particles, consisting of a chamber containing a supersaturated mixture of gas and vapor, the vapor condensing around ions created by the particle in its passing, thereby revealing the path of the particle. Also called expansion chamber, Wilson cloud chamber. Cf. bubble chamber.[1895-1900]
* * *
Radiation detector developed by C.T.R. Wilson.Its detecting medium is a supersaturated vapour (see saturation) that condenses around ions produced by the passage of energetic charged particles, such as alpha particles, beta particles, or protons. In a Wilson cloud chamber, supersaturation is caused by the cooling induced by a sudden expansion of the saturated vapour by the motion of a piston or an elastic membrane. In a diffusion chamber, the saturated vapour is cooled to supersaturation as it diffuses into a region kept cold by a coolant such as solid carbon dioxide or liquid helium.* * *
radiation detector, originally developed between 1896 and 1912 by the Scottish physicist C.T.R. Wilson (Wilson, C.T.R.), that has as the detecting medium a supersaturated vapour that condenses to tiny liquid droplets around ions produced by the passage of energetic charged particles, such as alpha particles, beta particles, or protons. In a Wilson cloud chamber, supersaturation is caused by the cooling induced by a sudden expansion of the saturated vapour by the motion of a piston or an elastic membrane, a process that must be repeated with each use.In a diffusion chamber, a simpler and continuously sensitive cloud chamber, the saturated vapour is cooled to supersaturation as it diffuses into a region kept cold by a coolant such as solid carbon dioxide or liquid helium.* * *
Universalium. 2010.
