Study On The Interactions Of Two Cold Atmospheric Plasma Jets

Atmospheric pressure cold plasma jet is a type of glow-like plasma generated technology, whose low-temperature characteristics and good control make it demonstrate some advantages in applied fields.However,the plasma generated has some restrictions in its area and size.In order to produce the plasma of scale required in the practical application,array of devices,as well as enlarged plasma jet devices have been designed and applied.Thus,study on the interaction between the plasma jets and performance of its nearness is a work of great significance.This paper mainly describes the interaction between the two atmospheric pressure He plasma jet with a ring-to-plane structure.By changing the various parameters of plasma jet: excited voltage,gas flow rate,electrodes distance,as well as the frequency of power supply, etc,we find the two plasma jets of a mutual angle of 30 degrees present not only mutual exclusion but also attraction between each other,and the combination of them have a great relationship to different experimental conditions.In the study of interaction between plasma jets of ring-to-plane structure,when the electrode distance is as smaller as 13mm,these two plasma jets can not be united in their parts of intersection,and they still appear obvious gap of gully,and with the increase of excited voltage the gap between jet channels is becoming larger.When the electrode distance is increased to 23mm,two channels of plasma jets are combination of nearness at the end of intersection parts with a lower excitation voltage.However,with increasing the voltage,they will be obvious separation and repulsion,which is due to the space charges of plasma that generate a Coulomb repulsive force between two jets.Through comparison experiment;we find this repulsion is the results of plasma columns and the gas flow.In the interaction between the plasma jets,the brightsome of discharge channels close is also observed,which is greatly influenced by the frequency of the applied power supply;and only can be observed at a higher frequency.Through compare of specific experiments and calculation,we find that the role of attraction is related to the existence of another electrode of plasma jet.At the same time,there are significant differences of appearance and discharge current waveform between single plasma jets with different power frequencies.In the experiment,when we transfer the gas flow rate of one plasma jets to low,then the gas between two jets channels will be breakdown and combined at high applied voltage.At the same time,we find the two plasma jets will present discharge imbalance with a larger electrode gap and a higher applied voltage. By compare the discharge currents of two plasma jets and single plasma jet,we find inhibition between with two plasma jets.This inhibition has something to do with the gas flow of the other jet.In the experiment,interaction of the plasma jets of pin-to-ring structure is also studied. We find the two plasma jets can get close in the part of intersection at a lower applied voltage, however,when the applied voltage is increased to a certain value,the two plasma jets will separate from each other,which is consistent with the experiment results mentioned above.At high gas flow rate and low applied voltage,the coalition of two plasma jets could be found.