Still in order to achieve flexible operating conditions, Pott et
al. [70] have developed a torch with a resonant cavity (see Fig.
26). Moreover the working gas flows with a superimposed
vortex. This kind of injection avoids wall burning and
stabilizes the discharge. This torch works with a pulsed power
supply, which limits the system heating while working with
high-energy amounts (and thus very energetic plasma species).