A system for generating and delivering a low temperature, wide, partially ionized tunable plasma stream is described. The system employs a fast rising, repetitive high voltage pulse generator, flowing gas, and a plasma head to produce the described atmospheric pressure plasma stream and its associated active species. The plasma head may have an exit slit with a relatively wide dimension to produce a relative wide plasma stream. Electrodes may be located proximate the exit slit, for example one in an interior of the plasma head via with gas flows toward the exit slit, and the other exterior to the plasma head and offset from the exit slit. The plasma may include baffle material to enhance a uniformity of flow through and across the exit slit. Plasma heads with having exit slit with different widths may be provided as a kit.