The Cloud Chamber – detecting radioactive particles at home

Have you ever notice the vapour trail left behind after airplanes jet through the air?

These trails, called contrails, are caused by aircraft travelling through the cold air at high altitudes. The trails are caused either by condensation of water vapor from the engine exhaust as it is ejected into the cold air, or by condensation of water vapor already in the air around pressure changes due to vortices formed as air passes over the aircraft’s wing. .

Well in 1932 Carl David Anderson announced his discovery of the positron, a positively charged electron. A discovery that was made using a cloud chamber, a relatively simple device, that can produce contrails when particles pass through the vapour sealed within the cloud chamber container. Continue reading