PLASMA GENERATION

The present invention discloses a plasma torch having an open end from which a plasma plume is emitted in use. The plasma torch comprises a central cathode rod and a grounded conductive tube. The grounded conductive tube has an open end and is arranged around the cathode and spaced therefrom to form a first cylindrical cavity open at one end. In use, an arc discharge between the cathode and grounded conductive tube ionizes a feed gas to produce a central thermal plasma emitted from the open end of the first cavity. The central cathode rod also comprises a tapered end which causes the locationof the arc discharge on the central cathode rod to be, in use, fixed at the tapered end of the cathode. The grounded conductive tube also comprises a lip which helps to control the energy distributionof the plasma plume emitted. Advantages of the present invention may be that the grounded conductive tube is interchangeable, thus a variety of lip geometries, and hence a variety of energy distributions, may be implemented,