The design for a cloud chamber is rather simple, and many factors can be changed without producing different results. There is one curious point that I've stumbled upon, though: The type of alcohol vapor used. I've read about methanol, ethyl alcohol, and isospropyl alcohol.

Will any of these choices produce different particle tracks? The factors I'm considering include the length of time the track exists for before it fades and the clarity of the track (i.e. opacity/transparency relative to the rest of the vapor).

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    $\begingroup$ Do you mean a bubble chamber or cloud chamber? Beside different operating points (temperatures and such) I don't think the material will make much difference in track size of particle detected. Beta's will make long skinny tracks because of relatively weak interaction and slow energy loss. Where as alpha's will be thick and short. (But I've never made a cloud chamber) $\endgroup$ – George Herold Jan 25 '15 at 13:54
  • $\begingroup$ I don't know enough about this to give a real answer, but I did find a good source: journals.aps.org/rmp/abstract/10.1103/RevModPhys.18.225 Unfortunately it does not discuss different types of alcohol but it does have sections that discuss some of the variables you are interested in. You might consider migrating this question to physics SE $\endgroup$ – willpower2727 Oct 6 '16 at 15:43

The only major difference the alcohol choice will make is the ionization energy. While the ionization energy for Methanol is 10.85 (source), ethanol is 10.62 eV, while Isopropyl is only 10.10 eV. The slight difference will allow for more molecules at the lower potential to be ionized, making for slightly longer trails. However, this shouldn't be a major impact. Design, flammability, corrosion, partial pressures, and other factors would be a bigger consideration.

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