| Improving Cloud Chamber Performance
| For over a century, scientists have used cloud chambers to study the paths of charged particles. First developed by Charles Wilson in the early 1900's (he received the Nobel prize in 1927 for this work), for 50 years cloud chambers were a standard tool for physicists looking at "elementary" paticles. In the past 40 years cloud chambers have been replaced in experiments by more sensitive apparatus and they are now generally only seen in demonstrations.
One unfortunate side-effect of this change is that many of the techniques used to make cloud chambers work well have been forgotten. It's easy to build a cloud chamber that works and gives an active region about 1cm deep. But experimenters in the 1940's and 50's reported building chambers with active regions 8cm deep or more. To anyone who has seen a cloud chamber with a deep active region, the difference is amazing. You get a sense of the reality of the particles flying through us all the time (about 1 cm-2 min-1 at sea level).
We'll be looking at some of the old papers and trying to resurrect the techniques that lead experimenters in the 50's to get such excellent results. The goal is to publish a cookbook for making a cloud chamber that a high school physics teacher can build and that has an active region more than 8cm deep.
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