Generation of a large-scale uniform plasma plume through the interactions between a pair of atmospheric pressure argon plasma jets

Abstract

In this Letter, a uniform air plasma plume with a fairly large scale is generated downstream of an air flow through interactions between a pair of argon plasma jets excited by a direct current power supply. With increasing power voltage, two separated plumes are first generated downstream of the pair of jets, which transit to the uniform planar plume with a fairly large scale. The planar plume elongates with the increasing air flow rate or power voltage. Moreover, the temperature of the planar plume is comparatively low with a maximum of about 80 °C, which is symmetrically distributed perpendicular to the pair of jets. For the separated plumes, discharge current is intermittently pulsed under a time-invariant gap voltage. However, both gap voltage and discharge current are periodically pulsed for the planar plume. High-speed video images reveal that the planar plasma plume stems from two discrete plumes flushing out of the pair of jets, which are soon merged together by a cathode-directed streamer due to interactions between them, leading to the generation of an arc-shaped filament. Due to the air flow, the arc-shaped filament keeps moving away from the jet vicinity until it quenches at last, which belongs to a glow discharge regime. In addition, surface modification of polyethylene terephthalate (PET) is performed with our planar plasma plume, which reveals that the hydrophilicity of the PET surface can be improved greatly.

Discharge aspects of a snake‐like plasma plume generated by an atmospheric pressure plasma jet with variable argon flow rate

“…Due to charge separation, [ 38 ] a layer of positive ions is left on the right side of the needle tip, which induces a field to enhance the applied one. [ 55 ] Under the effect of the sum ( E 0 ) of the applied field and the induced one, secondary electron avalanches in front of the positive‐ion layer develop towards and finally neutralize the positive ions, [ 39 ] leaving behind a new layer of positive ions that constitutes the new streamer head. Apparently, the propagation of the positive streamer is accomplished by successive generations of secondary electron avalanches.…”

Complicated streamer dynamics in petal‐like patterns formed on the substrate downstream of an argon plasma jet

“…The atmospheric pressure plasma jet, which can produce various reactive particles, offers a chamber‐less delivery of downstream reaction chemistry. [ 1,2 ] Due to these advantages, the plasma jet has great potential for applications spanning from biomedicine, [ 3,4 ] biocatalyst, [ 5 ] nano‐material synthesis, [ 6 ] surface modification, [ 7,8 ] to many other fields. [ 9,10 ]…”

“…The atmospheric pressure plasma jet, which can produce various reactive particles, offers a chamber-less delivery of downstream reaction chemistry. [1,2] Due to these advantages, the plasma jet has great potential for applications spanning from biomedicine, [3,4] biocatalyst, [5] nano-material synthesis, [6] surface modification, [7,8] to many other fields. [9,10] Plasma jet fed with inert gas normally operates in a streamer regime, [11] which is not the same as traditional positive streamer discharges, but features as composed of a plasma bullet propagating with a velocity of 10 3 -10 6 m/s.…”

Low-temperature argon plasma jet with cascading electrode technique for biological applications

“…One of the most important of these sciences is plasma and its essential applications, which have been very important in the development of science 3 – 7 . The use of plasma properties in surface activation, hydrophilicity and hydrophobicity, ozone generation, air pollution reduction, treatment of diabetic wounds, skin repair, treatment of cancerous tumors and numerous other applications is possible by using various plasma generation structures 4 – 13 . In the meantime, the use of plasma instruments is of particular importance due to their use in the synthesis of bio-surfaces as well as clinical tests 4 .…”

“…Plasma jet is one of the most essential plasma instruments used in this field 12 – 16 . Argon and helium plasma jets with different gas combinations are the most important instruments used in the area of bioplasma 13 – 17 . To plasma jets generate, various jet nozzle structures and power supplies with different electrical parameters can be used 17 , 18 .…”