Research On Portable Corona And Spark Air Plasma Jets At Atmospheric Gas Pressure

Atmospheric plasma jet is one of the hot research fields at home and abroad.There are many ways to produce plasma jet at atmospheric pressure.In this paper,two portable plasma jet devices are developed by comparing different jet generation methods and their characteristics,and corona discharge and spark discharge are selected as research objects.The main work is as follows:First,portable corona discharge device: first,by changing the voltage,electrode spacing and other ways to change the discharge of plasma jet intensity.It was found that the plasma jet ejected from the device is weak,and the plasma jet discharged by the corona contains a large amount of ozone(which is harmful to human health if inhaled for a long time).In order to overcome this shortcoming,a spark discharge device is developed.Second,portable spark discharge device: compared with corona air discharge device,the biggest advantage of spark air discharge device is that the plasma jet ozone content is very small and the jet strength is significantly enhanced.This is because the spark discharge device in the process of discharge can release stronger joule heat,discharging device inside the cavity of the plasma gas high temperature(8286?),under the high temperature quick decomposition of ozone.In addition,the schlieren image of spark discharge plasma shock wave jet was taken by high-speed camera,and the jet temperature was measured by thermocouple.Results showed that the effect of shock wave makes the ejected plasma jet gas temperature from 44? down to room temperature quickly,and therefore there is no heat damage to human body.Third,the characteristics of plasma jet in portable spark discharge device are studied in detail: First aspect,the factors affecting the length of plasma jet.By changing discharge conditions,the effects of different voltages and discharge spacing on the length of plasma shock jet were studied.The results show that the plasma jet length is positively proportional to the voltage.The length of plasma shock jet with different discharge spacing also has great influence.The optimum discharge conditions were 5000 V and 2 mm.Second aspect,preliminary study on the biomedical effects of plasma jet.The plasma jet was used to image the pig skin tissue.The results show that the light radiation from spark discharge can penetrate 6mm of pigskin tissue,and the light through the tissue can also stimulate multistage photoionization.It shows that the intensity of the high-energy spectrum is higher,and the high-energy photons can activate tissue cells,sterilize and diminish inflammation,and then promote wound healing.On the other hand the spectra measured by spectrometer reveal that the main component of plasma jet is nitric oxide.When nitric oxide is dissolved in the tissue fluid,it can promote the activation of the immune mechanism of cells,resist infection,promote wound heal,reduce scar and have other beneficial biomedical effects.