Class experiment The Taylor diffusion cloud chamber is a simple piece of equipment which will clearly show alpha particle tracks. It is cheap enough to allow students, in groups, the opportunity to do their own experiment. Students are fascinated by the tracks and watch them for a long time. This is something to be enjoyed and not hurried. You can do this as a demonstration. However, students will prefer waiting for their own apparatus to produce results rather than yours. Also, if you have eight to ten groups of students, each with their own cloud chambers, you are more likely to get some results sooner or later. See more details and video here : http://mariecurie.biz/blog/diffusion-cloud-chamber-930.html