Diffusion Cloud Chamber

Diffusion Cloud Chamber.....

The disadvantage of the cloud chamber lies in the fact that it needs a definite time to recover after an expansion. Hence it is not possible to have a continuous. Hence it is not possible to have a continuous record of events taking place in the chamber. This difficulty was removed by the introduction of the diffusion cloud chamber.

The outline of the apparatus is shown in diagram...

diagram    

If consists of a chamber containing a heavy get which is kept warm at the top and cold  at the bottom. Thermal gradient is maintained between the bottom and top of the chamber by external heating or cooling. The liquid (methyl alcohol) vaporises in the warm region. Where the vapour pressure is high.

The vapour  diffuses downwards continuously where the vapour pressure is low and condensation takes place. In available ions. The chamber remains continuously sensitive to lionizing particles until the supply of volatile liquid is exhausted. The system is illuminated by a strong source of light and the track of the particle is photographed by camera.