On the Electrical and Optical Features of the Plasma Coagulation Controller Low Temperature Atmospheric Plasma Jet

We report on the electrical and optical characterization of the Plasma Coagulation Controller (PCC) device, a low temperature atmospheric plasma source for biomedical applications. This device, designed for the study of plasma-induced blood coagulation, has been developed to operate flexibly in several operational conditions, since it is possible to vary the applied voltage Vp and the pulse repetition rate f in a quite wide range (Vp range: 2-12 kV, f range: 1-40 kHz). Emission spectroscopy measurements were conducted by varying the line of sight along the axis of helium and neon plasma plumes. The increase of the Reactive Oxygen and Nitrogen Species (RONS) has been observed, as one moves from inside the gas pipe to the outside, as a consequence of the gas mixture with the surrounding air. Furthermore, high-speed photographs of the plasma jet were taken, showing that the plasma is not uniformly distributed in a continuous volumetric region, the plasma being concentrated in localized structures called Pulsed Atmospheric-pressure Plasma Streams (PAPS). The propagation velocities of these objects have been examined, noting that they are not related to the propagation of ion sound waves. Rather, we provide indications that the streamer propagation speed is proportional to the electron drift velocity.