Electric charge spectrum of recoiling 218Po

The chemical and physical properties of a radioactive nanometric aerosol are important in determining its behaviour in indoor atmospheres and play a major part in determining its potential health effects. In a well defined experimental system, mass spectrometry coupled to the Time-of-Flight technique, we measured the electric charge of 218Po at the end of its recoil path. The charge distribution of the recoiling 218Po is mainly neutral and singly charged with a very small multicharged fraction. In case of radon progeny embedded in solid matter this one can play a major role in the surface ionisation processes versus electron and ion emission induced by the passage of the alpha recoils through the surface