Cloud Chamber
From UO Physics Demonstration Catalog
Return to Nuclear Physics
Description:
The cloud chamber makes it possible to view the tracks left by particles emitted by a radioactive source. The cloud chamber consists of a lower chamber that can be filled with Liquid Nitrogen. An upper chamber sits on top of the Liquid Nitrogen chamber. The Upper c Chamber which is saturated by alcohol vapor from adding alcohol to a pad toward the top and a layer of alcohol on the bottom plate inside the chamber. A high voltage power supply is connected to the chamber plates.
To enhance visibility a bright light source from a projector shines into lower of the upper chamber. Once the plate at the bottom of the observation chamber cools down, due top the Liquid nitrogen in the bottom and the high voltage is initiated, the air near the plate becomes supersaturated with alcohol vapor and tracks will become visible as the particles from background radiation causing the alcohol to condense. Add the rod that has some radium into the chamber and you will see tracks coming from the rod. It is possible to distinguish between alpha and beta particles and gamma rays due to the length and paths of different tracks.
SAFETY NOTE: DO NOT TOUCH THE METAL PART OF THE RADIOACTIVE ROD. YOU CAN WEAR LATEX GLOVES AND BE SURE TO WASH HANDS IF CONTACT WITH THE ROD OCCURRED.
Location:
- Cloud Chamber: Shelf L-1
- High Voltage Power Supply: Shelf K-3
- liquid N2 dewars: Shelf E-4
- Ethanol: Chem Hood
