Even ignoring the irony that thorium oxide is primarily an alpha (He +) emitter and thus not a ‘negative ion’ source (which would be beta decay, with e –), thorium oxide isn’t something ...

Alpha decay (two protons and two neutrons ... A periodic table shows that element number 90 is thorium, \(_{90}^{234}\textrm{Th} ...

While thorium only releases alpha particles, in doing so, it becomes radium which will then, eventually, release a beta particle and ... Radioactive decay could also cause hot spots on digital ...