text: Plasma spraying systems can be categorized by several criteria.
  Plasma jet generation:
  *direct current (DC plasma), where the energy is transferred to the plasma jet by a direct current, high-power electric arc
  *induction plasma or RF plasma, where the energy is transferred by induction from a coil around the plasma jet, through which a radio-frequency current passes. This electrode-free technology allows to produce coatings with high purity and high density.
  Plasma-forming medium:
  *gas-stabilized plasma (GSP), where the plasma forms from a gas; typically argon, hydrogen, helium or their mixtures
  *water-stabilized plasma (WSP), where plasma forms from water (through evaporation, dissociation and ionization) or other suitable liquid
  *hybrid plasma – with combined gas and liquid stabilization, typically argon and water
  Spraying environment:
  *atmospheric plasma spraying (APS), performed in ambient air
  *controlled atmosphere plasma spraying (CAPS), usually performed in a closed chamber, either filled with inert gas or evacuated
  *variations of CAPS: high-pressure plasma spraying (HPPS), low-pressure plasma spraying (LPPS), the extreme case of which is vacuum plasma spraying (VPS, see below)
  *underwater plasma spraying
  Another variation consists of having a liquid feedstock instead of a solid powder for melting, this technique is known as Solution precursor plasma spray