Abstract: A method for non-invasively measuring the impedance of a plasma discharge. Parallel anode and cathode electrodes are connected to a DC voltage source that ignites and sustains a plasma between the anode and cathode. A network analyzer applies a frequency-swept AC signal superimposed onto the DC voltage applied to the electrodes. The voltage of the AC signal reflected by the plasma is measured by the network analyzer through one of the electrodes used to sustain the plasma and is used to find the complex impedance of the plasma as a function of the applied AC frequency. Since the electrode serves dual purposes, the insertion of an additional physical probe that could introduce perturbations or contaminate the discharge is not necessary.

Abstract: An apparatus and methods to increase and direct the spatial volume of atmospheric pressure plasma jets. One or more additional gas flows is introduced to intersect the plasma jet. As the plasma jet interacts with these additional gas flows, the direction of propagation of the plasma jet is altered, the plasma expands into the volume defined by the additional gas flow, and the volume and effective surface area of the plasma jet increases accordingly, while the power increase needed to drive the increase in plasma volume scales sub-linearly with the increase in volume.

Abstract: An apparatus and methods to increase and direct the spatial volume of atmospheric pressure plasma jets. One or more additional gas flows is introduced to intersect the plasma jet. As the plasma jet interacts with these additional gas flows, the direction of propagation of the plasma jet is altered, the plasma expands into the volume defined by the additional gas flow, and the volume and effective surface area of the plasma jet increases accordingly, while the power increase needed to drive the increase in plasma volume scales sub-linearly with the increase in volume.