Old fashioned cloud chamber

Old cloud chamber using dry ice and Americium 241.

This is an old model I built some time ago. The acrylic box comes from an old napkin holder (hence the little studs on the top) and the Styrofoam base was cut from stereo packaging. Styrofoam is the way to go if you want your dry ice to last for a bit longer, but hopefully I don't need to find dry ice anymore if my peltier coolers work! For the bottom I used a thin sheet of Aluminium that you can buy at Home Depot or any hardware store. beneath the chamber, inside the Styrofoam there is a little pocket for putting dry ice and I placed some Aluminium foil on top of it as well as the Aluminium sheet that I sprayed black to be able to visualize the particle tracks. Along the inside of the chamber I used these sticky felt pads that are usually used to put under the legs of furniture; these ones were a bit absorbent and were able to soak up the isopropyl alcohol quite well.  I left the top and one side clear for viewing, but the glare of the plastic was always irritating and always blocked the viewer from properly seeing the particle tracks. Hopefully in my electric model the viewing angles and lighting will be better. I'm currently trying to find a thin plastic piece that is dome-shaped, but not too flimsy. I already have the rubber for the seal, but am still missing a good computer power supply; all the ones I buy end up being duds...Anyhow I thought I would post my old project just so people can have an idea of what the old version looked like.