Building your own cloud chamber to make particles real
Francisco Barradas - Solas (text), Paloma Alameda - Melendez (comic book)
It is not easy to justify the choice of isopropyl alcohol (isopropanol) or to explain in detail how supersaturation happens...
If you want to go into the details about how the cloud chamber works, you cannot do better than study the papers published while it was being used a research instrument. For instance:
Many of these articles are available at http://hep.ucsb.edu/people/hnn/cloud/
Or you can go to the classic book written by JG Wilson:
Wilson, J. G. 1951. The Principles of Cloud-Chamber Technique. Cambridge: Cambridge University Press.
which is available as a pdf file at the Internet Archive:
But perhaps the most detailed exposition of the continuously sensitive diffusion cloud chamber operation principles can be found in the (1937) PhD dissertation of its inventor, Alexander Langsdorf, available at DSpace@MIT, MIT's online institutional repository: http://dspace.mit.edu/bitstream/handle/1721.1/10857/35319592.pdf?sequence=1
If you want to know more about cosmic rays than you can learn in the popular science literature, try the Review of Particle Physics 2008, which you can access here: http://pdg.lbl.gov/2009/reviews/rpp2009-rev-cosmic-rays.pdf