Process gas

The process gas is the gaseous precursor used for plasma stimulation. Dependent from the chemistry of the process gas much different plasma effects can be stimulated. Therefore a hugh variety of process gases is used for plasma treatment. In case of an Atmospheric Plasma the choice of process gases is restricted to those which can be handled in the free atmosphere. In case of a low pressure plasma generally any gaseous substance can be used for a process gas including those (mostly organic) substances which are liquid under atmospheric pressure but can be evaporated and are gases under low pressure conditions.

Most important process gases are: 

Oxygene, Hydrogene, Nitrogene, Tetrafluormethan, Argon, Sulfurhexafluoride, Air,...

Process gas
The colour and intensity of a low pressure plasma indicates density and puridity of the plasma.