My cloud chamber adventures started with the LHC Rap video on YouTube that a friend at work shared. I forwarded the link to my son's teacher the week before the first parent teacher meeting of the 2008-09 school year. Last year I brought demonstrations of oobleck and sodium acetate for a presentation. She invited me to come back this year. It is a 5th-6th grade class. In science this year they were studying models. The LHC was a perfect fit, trying to find the Higgs Boson and prove the standard model. The video was a good start but I needed to bring some kind of demonstration. I thought of a cloud chamber.
My search for information on cloud chambers started with Instructables.com but there was nothing. I did find some cloud chambers for sale, websites about cloud chambers, and YouTube videos demonstrating traces in cloud chambers. Then I found Holly Batchelor's video. It had step by step instructions. It was just what I needed. I set off to work. I used an aluminum griddle cut down to fit in the foam cooler that I cut down to hold the dry ice. I used the reptile house Holly used and painted parts of it black instead of sewing the drape. Add some alcohol and dry ice and my kids and I were watching sub atomic particle traces in my garage. Very cool. I shot some video and uploaded this one to YouTube. This video has a clear trace at the end that I believe it is an electron initiated by background radiation.
I also was able to produce Alpha particle traces by placing Americum 241 from a smoke detector in the chamber.
I ended up doing two presentations at school one group included my daughter's class and one included my son's. Some of the kids were interested in the LHC and the cloud chamber, and some others were fascinated by the dry ice bubbling in water and the other dry ice I had filling up a large mylar tube. I hope the kids got something out of it, I know I had fun.