(or Cold Plasma)
In physics and chemistry, plasma is known as the 4th state of matter similar to gas in which a certain portion of the particles are ionized and there are free electrons present. Based on the relative temperatures of the electrons, ions and neutrals, plasmas are classified into thermal plasmas and non-thermal plasmas.
Thermal plasmas form at elevated (very high) temperatures and as such all have electrons, ions and neutrals are at an equilibrium (hot) thermal state. Non-thermal plasmas, however, have the ions and neutrals normally at room temperature whereas electrons are much “hotter”, usually due to electrical excitation.
The sun, stars and thunderstorm lightning are examples of thermal plasmas while the glow discharge in a fluorescent tube are examples of non-thermal plasmas that are common.