Hello all, My son and I have been doing experiments with a simple cloud chamber and I am curious what type of accelerator I might be able to build that would be strong enough to make positrons? Then I will use a magnet with the cloud chamber to show him that they are charged differently. A note, I am aware that I will still need to research the proper safety precautions before actually using it. Any suggestions or help with this project would be great. Thank you.