Cloud Chamber Experiment

Prep Time:

45-60 minutes

Cook Time:

Wear gloves when handling dry ice to protect from frostbite.
Ensure the area is well-ventilated when using isopropyl alcohol to avoid inhalation of fumes.
Never seal the container completely airtight as the pressure from the dry ice could build up.

Serves:

14+ years

Level:

Servings

About the Recipe

Understand the basic principles of particle physics and radiation detection.
Explore how ionizing radiation interacts with alcohol vapor to form visible tracks.
Learn about natural background radiation and cosmic rays.

Prepare the Cloud Chamber: Line the bottom of the metal container with black felt. Ensure the felt covers the entire surface evenly.
Soak the Felt: Generously soak the black felt with isopropyl alcohol. The felt should be wet but not dripping.
Set Up Dry Ice Base: Place a substantial amount of dry ice in a sturdy tray or container that can safely hold the metal container.
Place the Chamber on Ice: Set the metal container on the dry ice. Ensure it has good contact to cool down quickly and evenly.
Seal and Wait: Close the lid of the container and wait about 10 minutes for the alcohol vapor to become supersaturated within the cooled chamber.
Observe Particle Tracks: Use a flashlight to shine light into the chamber and observe from above. Look for streaks or trails in the mist, which are caused by ionizing particles.