Build this simple cloud chamber at home and detect cosmic-ray muons, electrons, and alpha particles!
Different particle trail types you can see:
Inside the bottom of the cup, sandwich a section of felt between 2 magnets — one inside the cup, the other on the outside.
Wearing safety glasses, pour
in just enough isopropyl alcohol to completely soak the felt.
Form a Play-Doh seal about ½” thick on the cup rim to avoid any alcohol vapor leakage between the cup and metal plate.
Wearing an insulated apron and gloves, put some dry ice into the styrofoam cooler lid. Place the metal plate on top and wait until the surface becomes very cold.
Invert the cup on the metal plate and press firmly so that the cup sticks to it. That’s it!
TIP: If your Play-Doh becomes too dry after coming in contact with isopropyl alcohol, try substituting plasticine modeling clay.
With the lights off, use your flashlight to illuminate the area inside the cup closest to the plate.
After 2–3 minutes the alcohol vapor will cloud into a supersaturated state. When an electrically charged particle zips through, it will ionize the vapor atoms by ripping off the electrons along its path. This will trigger the condensation process and we can see a trail from the charged particle!
