Abstract: A plasma torch having an open end from which a plasma plume is emitted in use is disclosed. The plasma torch includes a central cathode rod, a grounded conductive tube having an open end and being arranged around the cathode and spaced therefrom to form a first cylindrical cavity open at one end; and a high voltage electrode having a dielectric barrier material at a radially inward-facing surface thereof and being arranged around the grounded conductive tube and spaced apart therefrom to form a second annular cylindrical cavity open at one end. A constant direct current (DC) electrical power plus a high voltage pulsed electrical power is provided to the cathode producing an arc discharge in the first cavity between the cathode and grounded tube to generate a central thermal plasma emitted at an open end of the first cylindrical cavity.

Abstract: A plasma torch having an open end from which a plume of plasma or plasma effluent, for use in therapeutic treatment of tissue in vivo, preferably skin and/or wounds, is emitted in use. The plasma torch comprising: a cathode rod; and a grounded conductive tube having at least one opening and being arranged around the cathode and spaced therefrom to form a cavity in which, in use, an arc discharge between the cathode and grounded conductor ionizes a feed gas to produce a thermal plasma, the plasma or effluent being emitted in a plume from the opening of the grounded conductor. The opening of the grounded conductor tube comprises a lip, the inwardly facing surface of which defining an orifice, the orifice having a length to an opening width ratio of at least 2.5:1.

Abstract: A plasma torch having an open end from which a plasma plume is emitted in use is disclosed. The plasma torch includes a central cathode rod, a grounded conductive tube having an open end and being arranged around the cathode and spaced therefrom to form a first cylindrical cavity open at one end; and a high voltage electrode having a dielectric barrier material at a radially inward-facing surface thereof and being arranged around the grounded conductive tube and spaced apart therefrom to form a second annular cylindrical cavity open at one end. A constant direct current (DC) electrical power plus a high voltage pulsed electrical power is provided to the cathode producing an arc discharge in the first cavity between the cathode and grounded tube to generate a central thermal plasma emitted at an open end of the first cylindrical cavity.