Abstract: Facilities for introducing an additive of arbitrary material state to a plasma stream in a plasmatron is described. An arc discharge established between the cathode and the anode of the plasmatron cooperates with a stream of ionizable gas introduced into the region between such electrodes to produce a plasma stream in a direction toward the anode. An outlet nozzle axially disposed in the anode for ejecting the plasma stream under pressure communicates with an oblique passage extending through the anode for the introduction of the additive into the plasma stream. A plasma stabilization arrangement in the form of apertured plates are disposed in the space between the anode and the cathode, the apertures in the plates being coaxial with and having a diameter larger than the diameter of the nozzle.