Cloud Chamber

This little video represents success at a project that I have tried to make several times over many years with no joy until recently.

 

A cloud chamber is a device that allows you to see the paths of otherwise invisible radioactivity. A particle (in this case alpha) shoots through the air creating a lot of ionized atoms. If the conditions are right , with supersaturated alcohol vapor. The alcohol condenses on the ions creating a cloud.

 

I've tried building a chamber with dry ice several times with no results. A few years back I built a chamber using peltier elements. It got plenty cold but I never saw a single track.

 

A few days ago I grabbed the peltier system for another try but one of the leads on the unit had fallen off (cheap components) and since I had thermal epoxied everything together that was that.

 

I was actually kind of mad at the whole thing at this point but decided to try a simple liquid nitrogen chamber that I had tried a few years ago (and failed). For some stupid reason it worked perfectly. Loads of tracks.

 

So today I spent some time trying to get a good video. To do that I cut a hole in the side of the plastic chamber and covered it with a good glass window. Keeping things reasonably clean if hard, it reminded me of schlieren photography. Every dust particle shows up like a little searchlight.

 

The video shows the run from start to end. The chamber cools down fairly quickly because of the liquid nitrogen, but I still speeded up parts of the video to keep it short. I wanted to show how adding a clearing voltage to the chamber can really add to the number of tracks that you can see.

 

The chamber is really a wonder to see in person. the tracks look like fairy tale effects, ghostly and real at the same time.

 

Cheers.

 

 

Done