I attended the IoP make and take workshop to build my own fish tank cloud chamber last Thursday and it was a great experience! The workshop was organised and led by Cerian Angharad and held at St Teilo’s CW School. The tank is really easy to build and quite cheap too. All you need is some sticky felt, which you stick at the top (which is actually the bottom of the tank) and soak with alcohol, a plastic fish tank, a metal tray, on which the top of the fish tank needs to be stuck to with duck tape and you’re done. The rest is a normal shallow tray that can be found in most school labs, a sheet of polystyrene to rest on the bottom of the tray and dry ice that goes between the polystyrene and the tray with the fish tank resting on it. See the photo below to have a better idea!
The rod in the middle of the tank is a radioactive welding rod which emits alpha particles. The chamber works really well and you can soon see lovely traces from the alpha particles emitter by the rod. Some of the tanks that were made also showed very clearly cosmic rays/background radiation coming into the tank from the sides.
This is one of the best workshops I have even been to and the tank is great for radioactivity demonstrations, as the whole class can gather around it and see what’s going on. I will certainly run the workshop in my area in Gloucestershire, so contact me if you are interested in attending. If you are too far from Gloucestershire, find your IoP Network Coordinator here and ask them if and when they will run this workshop in your area!
Watch the video below to get a feeling for what you will see in your tank!