ionization, ionisation(noun)

the condition of being dissociated into ions (as by heat or radiation or chemical reaction or electrical discharge)

"the ionization of a gas"

ionization, ionisation(noun)

the process of ionizing; the formation of ions by separating atoms or molecules or radicals or by adding or subtracting electrons from atoms by strong electric fields in a gas

ionization(Noun)

any process that leads to the dissociation of a neutral atom or molecule into charged particles ions; the state of being ionized