Monday, May 7, 2012
Simple cloud chamber
A cloud chamber shows alpha particles being emitted from americium sources. The chamber works by creating a layer of supersaturated alcohol vapor which visualize the radation. The alpha particles trigger condensation in trails through the vapor cloud and show up as tiny droplet tracks. In this chamber, I have two alcohol-soaked pads above an aluminum plate that is cooled by dry ice. The pads emit alcohol vapor, which is cooled by the air above the aluminum plate to the point where it is colder than would normally by necessary to condense. The tiny radioactive particle pushes it over the edge to cause condensation, which is visible droplets.