The high pressure torch discharge plasma source

Abstract

We present a plasma source which works on the principle of the arc torch discharge. The powered electrode of the arc torch discharge was made from a thin pipe that simultaneously acts as the nozzle through which the working gas flows to the discharge region. The flow of the working gas stabilizes the arc torch discharge and a well defined plasma channel is created. The advantage of this system is that it is able to work at high pressure of working gas up to atmospheric pressure inside the plasma-chemical reactor and also in free space.

Nitric Oxide Generation with an Air Operated Non‐Thermal Plasma Jet and Associated Microbial Inactivation Mechanisms

“…The findings can be explained by the reaction chemistry at elevated temperatures. Although the temperature of the plasma in the microhollow cathode discharge geometry is considerably colder than, for example, for arc discharge plasmas, the temperature is still well above room temperature and therefore the generation of ozone is inhibited. Accordingly, NO seems crucial for the observed inactivation of microorganisms at a distance of 10 mm .…”

Plasmas for additive manufacturing

“…The earliest known demonstration was surface cleaning with a microplasma jet, referred to in the original publications as a plasma pencil and shown in Figure 2a, [ 33 ] to selectively remove corrosion without damaging pristine regions in archeological artifacts. [ 34 ] Tailoring the gas chemistry makes it possible to remove challenging materials such as silicon by dry or reactive ion etching, and by rastering the microplasma jet, arbitrary pattern transfer is possible in three dimensions, one example of which is shown in Figure 2b.…”

Hollow cathode sustained plasma microjets: Characterization and application to diamond deposition

“…Similar flow effects have been observed in rf discharges in high velocity gas flow where shock waves were observed. 11 Turbulence could increase mixing with air at some distance from the exit of the tube 15 thereby causing the discharge to extinguish at increased gaps. It should be noted that plasma microjets could not be formed when flowing air at atmospheric pressure using the 178 m diameter tube but operation at lower pressures (Ͻ400 Torr) was possible.…”

“…Although atmospheric operation was achieved in one case, the discharges were found to form on the surface of the electrodes. 11 Operation at high pressures in the hollow cathode mode requires shrinking of the hole diameter to sizes similar to those found in planar microdischarges such that the pressure times hole diameter (p•d) is on the order of 10 Torr cm. 1 Formation of microdischarges in a flow geometry would take advantage of the properties of a hollow cathode and could be attractive for thin film deposition.…”