Ionized particles, condensation chambers, simple cans, sponges… finding the proper position next to a window… I think an alchemist always has something to learn from inspirational readings. Cloud chamber models for detecting nuclear events from Clair L. Stong, The Scientific American book of projects for the amateur scientist.
Taken from a correspondence of mine with an actual physicist:
“… I have attached the entire chapter (the book is Clair L. Stong, The Scientific American book of projects for the amateur scientist). Several cloud chamber models are described there; the one I built is shown in Figure 134 (one of the less complex versions).
The operating principle is very simple: alcohol evaporates from the sponge on the top of the can and – as it diffuses downwards – becomes supersaturated due to the temperature gradient (under the can, there is solid CO2). When an ionizing particle, typically muons, passes into the supersaturated zone that forms a few centimeters above the dry ice, the ionization of the air causes the alcohol to condense, which is visible as a thin thread.
You have to have some luck with the position of the window, as the “sensitive” zone depends on the material of the can… the better it conducts the heat, the higher up – in the can – the transition takes place. Dry ice can be wrapped in cloths to move the area, but, of course, the cloth cools down little by little, and the optimal conditions vanish. Another critical element is the external light, which must be at the right angle (tests are carried out…) and must not heat the steam. Otherwise, the convective motions become too strong, and the delicate condensations vanish too quickly or form altogether.