An electrosurgical apparatus for generating a plasma discharge beam is provided. In one aspect, the electrosurgical apparatus includes a first fluid flow housing, a second fluid flow housing, and an electrode. A first gas is provided to the distal end of the first fluid flow housing, where the electrode is energized to ionize the first gas and generate a plasma discharge beam. A second gas is provided to the distal end of the second fluid flow housing, where the distal end of the second fluid flow housing injects the second gas into the plasma discharge beam. In another aspect, the electrosurgical apparatus includes a single fluid flow housing having an external electrode and an internal electrode. In another aspect, the electrosurgical apparatus includes a transformer assembly having a plurality of serially-connected transformers.