We recommend using a glass container and a flexible metal pie pan OR a glass container you can seal in some other way. 

• Getting that seal is important for getting the necessary supersatured alcohol environment.

Although we found shape to not be a major factor in our cloud chambers, we progress towards a prism with a circular base (circular container).

• We found this allowed for easy viewing of the inside of the container and, in theory, would allow for better air circulation within the chamber.

We recommend basing your design around how you intend to achieve the necessary temperature gradient between the cold base and warm top.

Our design focused around the use of dry ice.

• We used dry ice to cool the base, but Peltier coolers could also provide good results

• Ensure the dry ice is in direct contact with a metal base

• The base MUST be metal or another highly conductive material

• We believe our sheet metal pie pan had a coating on it that reduced its conductivity

• We found using a large chunk of dry ice to be better than many small pieces

• Additionally, double-stacking dry ice like we did in design #5 may help.

To achieve the necessary warm temperature (~40°C) for the top of the chamber, we recommend using a heat gun, hair dryer, or container of warm water.

We recommend using felt over foam, especially spongey foam, because felt does a better job at absorbing the alcohol

• Absorption is important for getting enough alcohol into the chamber in order for supersaturation to be possible

• Isopropyl alcohol was the easiest for us to use and was cost-effective

If you want a good view of the cloud chamber's contents, we suggest using a ring of felt so that you can view the chamber from top-down.