Patent ID: 7589473

Claim:
A device for generating pulses of plasma comprising: a. an anode; b. a cathode assembly comprising (i) one or more cathodes, and (ii) a cathode holder; c. a plasma channel, extending longitudinally between said cathode assembly and through said anode, and having an outlet opening at the anode end, a part of said plasma channel being formed by two or more intermediate electrodes electrically insulated from each other and the anode, the plasma channel comprising a heating portion closest to the cathode assembly, an anode portion, and an expansion portion between the heating portion and the anode portion, the expansion portion having two or more sections with the diameter of each successive section of the expansion portion increasing toward the anode; and d. an extension nozzle connected to the anode end of the plasma channel and forming an extension channel having a tubular insulator covering a portion of the inside surface of the extension channel.