New hybrid source of cold atmospheric plasma

New cold atmospheric plasma sources that combine microwave plasma with the hollow cathode plasma generated simultaneously by a common hollow electrode are described. A laboratory prototype of a hybrid hollow electrode activated discharge (H-HEAD) source with simple cylindrical electrode is presented. The hollow cathode plasma is generated by a pulsed DC power. The source is capable to generate over 15 cm long plasma plumes in open air at microwave power of 500 W at less than 500 sccm of argon flow. Parameters of the hybrid plasma plume are controlled by both the microwave generator and the hollow cathode power generator.