Paris, France/parisF565

Previous | Home | Next

The ionization chamber. A radioactive sample is placed on the tray inside the ionization chamber. The radioactivity of the sample causes the air to ionize, which then establishes a current. (This effect is the same as is used today in a smoke detector, which has a sample of radioactive americium in a tiny ionization chamber, which conducts electricity as long as the air is not contaminated with smoke. When smoke from a fire pervades the space, the smoke particles absorb the ions and the air is no longer conductive, which trips an alarm.)