[Can detect: Alpha, Beta and Gamma]
- Figure above shows a simple form of cloud chamber, a device which enables the tracks of charged particles to be seen.
- The felt ring round the top of the chamber is soaked in alcohol. The bottom of the chamber is cooled by ‘dry ice’ (solid carbon dioxide) to around -80 °C.
- As the alcohol vapour spreads downward through the chamber, it is cooled beyond the point at which it would normally condense.