A plasma apparatus comprising: a first anode plasma head r and a first cathode plasma head each comprising an electrode (45a,b) a plasma flow channel, a plasma head axis, and a primary gas inlet disposed between at least a portion of each of said electrodes and said plasma flow channels, each of said plasma flow channels comprising a first generally cylindrical portion, adjacent to said electrode, having a diameter D1, a second generally cylindrical portion, adjacent to said first portion, having a diameter D2, and a third generally cylindrical portion, adjacent to said second portion, having a diameter D3, wherein D1<D2<D3; said first anode plasma head axis and said first cathode plasma head axis being disposed at an angle α relative to one another; and a second anode plasma head and a second cathode plasma head each comprising an electrode (45a,b), a plasma flow channel, a plasma head axis, and a primary gas inlet disposed between at least a portion of each of said electrodes and said plasma flow channels, each of said plasma flow channels comprising a first generally cylindrical portion, adjacent to said electrode, having the diameter D1, a second generally cylindrical portion, adjacent to said first portion, having the diameter D2, and a third generally cylindrical portion, adjacent to said second portion, having the diameter D3, wherein D1<D2<D3; said second anode plasma head axis and said second cathode plasma head axis being disposed at an angle α relative to one another; said first anode plasma head and first cathode plasma head being 30 disposed in a first plane and said second anode plasma head and said second cathode plasma head being disposed in a second plane, said first and second planes being disposed at an angle β of between about 50 to about 90 degrees to one another. a first anode plasma head r and a first cathode plasma head each comprising an electrode (45a,b) a plasma flow channel, a plasma head axis, and a primary gas inlet disposed between at least a portion of each of said electrodes and said plasma flow channels, each of said plasma flow channels comprising a first generally cylindrical portion, adjacent to said electrode, having a diameter D1, a second generally cylindrical portion, adjacent to said first portion, having a diameter D2, and a third generally cylindrical portion, adjacent to said second portion, having a diameter D3, wherein D1<D2<D3; said first anode plasma head axis and said first cathode plasma head axis being disposed at an angle α relative to one another; and a second anode plasma head and a second cathode plasma head each comprising an electrode (45a,b), a plasma flow channel, a plasma head axis, and a primary gas inlet disposed between at least a portion of each of said electrodes and said plasma flow channels, each of said plasma flow channels comprising a first generally cylindrical portion, adjacent to said electrode, having the diameter D1, a second generally cylindrical portion, adjacent to said first portion, having the diameter D2, and a third generally cylindrical portion, adjacent to said second portion, having the diameter D3, wherein D1<D2<D3; said second anode plasma head axis and said second cathode plasma head axis being disposed at an angle α relative to one another; said first anode plasma head and first cathode plasma head being 30 disposed in a first plane and said second anode plasma head and said second cathode plasma head being disposed in a second plane, said first and second planes being disposed at an angle β of between about 50 to about 90 degrees to one another.