Since plasma is simply ionized gas (ie. charged particles), with the exception of neutron ejection (no charge) and gamma radiation (photons), can the natural decays of an isotope be modeled as plasma?
Is there some lower density limit for plasma models to be valid? Would something like the daughter particles of alpha decay, a single He+2 charge and a single daughter-2 charge be effectively plasma? (or more technically, 2 different plasmas)
Let's assume this radioactive decay is happening in a vacuum like outer space for example. Within the walls of a vacuum chamber are these decayed charged particles plasma? And more importantly, if there are many (ie. lots of radiation from the fuel source), will the particles collectively behave like plasma?