How to Build a Cloud Chamber
Project overview: This is a cool physics project that allows the person to actually view the tracks of the subatomic particles like cosmic rays and radioactive particles that pass through the air.
Materials required:
A clear plastic container (storage bin or tall glass fishbowl turned upside down)
A thick aluminium plate
High purity isopropyl alcohol
Dry ice
Bright LED flashlight
Felt
Instructions:
To prepare the chamber, line the top of the container or bottom when inverted with a thick piece of felt and soak it thoroughly with the high purity isopropyl alcohol
Place the aluminium plate on a bed of dry ice. Then, place the container onto the plate and seal the edges with tape to make it airtight.
To create the gradient, as the base becomes really cold, the felt at the top remains at room temperature. Therefore, a layer of supersaturated alcohol vapor forms near the plate.
After about 5-10 minutes dim lights in the room and shine the LED flashlight horizontally through the chamber just above the aluminum plate. Some faint wispy containers like jet places should appear and disappear. These would be the paths left by cosmic rays from outer space passing through the container.
Explanation:
The cold base creates a region of supersaturated alcohol vapor. When the high-energy cosmic rays pass through, they would ionize the vapor and leave a trail of liquid droplets that represent the particle's path. Therefore, this allows us to visualize the subatomic interactions that are normally invisible.
