christo

I think it is radon which builds up on the surface of any highly charged body due to polarisibility effects. This also happens near high voltage power lines. You can do the same trick with an air ioniser: high count rate from the radon and radon daughters. Chris

It is radon which is attracted to the high electric field. This deposits radon daughters and that is where the ballistic radiation is from. You can do the same trick with an air ionizer. If you use one with a filter, the radon builds up on the filter. Lots of beta and alpha and gamma. Chris