Miniaturized Noble Gas Plasma Jet

The Miniaturized Noble Gas Plasma Jet has originally been designed to be inserted into the working channel of a conventional endoscope. It has a tube-like character, is flexible, very thin and generates a biologically active jet plasma at the gas outlet. The device consists of an inner plastic tube, a ceramic nozzle, an outer plastic tube and a metal wire. The inner plastic tube is plugged upon the thin end of the ceramic nozzle. In order to provide high voltage at the end of the tube and at the same time maintain tube flexibility the metal wire is coiled around the inner tube. The outer plastic tube is placed coaxially over the inner tube. Thus, two gas channels are created. Through the inner tube helium or neon feed gas is provided with moderate flow rates of up to 300 sccm. The resulting gap between the inner and the outer tube is used to bring a second gas (CO₂) to the gas nozzle that acts as shielding gas. Due to the use of feed and shielding gas a stable plasma jet is generated even in hollow bodies. The original development was funded by the German Federal Ministry of Education and Research (BMBF) under the grant numbers: 13GW0052C and 03Z22DN12.

Due to the small dimensions, the high flexibility and the capability to work in cavities and hollow bodies, the system has subsequently been adapted to further areas of application, such as the inactivation of viruses in the upper respiratory tract.