Study On Optical And Electrical Characteristics Of A Pin-to-plate Dielectric Barrier Discharge

From the viewpoint of economic cost and portability,a dielectric barrier discharge(DBD)with pin-to-plate electrodes was designed by using atmospheric air or Ar as the working gas.Optical and electrical characteristics of the DBD were studied by electrical and optical methods at the AC power excitation.The Lissajous figures were obtained from the applied voltage and the transported charge signals to calculate the applied power(P).The vibrational temperature(T_v)of nitrogen molecules was calculated by the Boltzmann plot method for the second positive system sequence band group of the plasma emission spectrum.And the electron excited temperature(T_e)was calculated by the relative intensity ratio method using the lines at 763.51 nm and 772.42 nm in the Ar emission spectrum.The water contact angle of the glass surface was measured by the image processing method to study the hydrophilic properties of the glass surface after plasma treatment.First,the DBD in air at atmospheric pressure,P as a function of the applied voltage(V_a),the gap distance(d),and the gas flow rate were studied.And the discharge phenomenon and Lissajous figures were obtained.It is found that P increases with the increase of V_a and the gas flow rate,and decreases with the increase of d.In addition,the spectral lines of 200-1100 nm spectra generated by the DBD in air at atmospheric pressure were collected using a spectrometer and found to be mainly the spectral lines for the transitions of the second positive system of the nitrogen molecules.T_v was studied as a function of d,V_a and the electrode diameter for the single-layer and the double-layer DBD.For a given d,the breakdown voltage was lower for the single-layer DBD,but T_v was higher.T_v also increases with the increase of V_a and the electrode diameter.Then,plasma emission spectrum was measured in Ar DBD at atmospheric pressure to study the relationship between T_e with V_a and d.When V_a and d increase,T_eincreases slightly.This is qualitatively explained by the inelastic collision between high-energy electrons and the particles in the working gas.Finally,the application of the DBD in surface modification of the glass was studied,and the hydrophilic properties were observed by the change of water contact angle.The longer plasma treatment time,the more obvious modification effect.This work has practical value for industrial application and is an effective means of improving glass surface moisture.At atmospheric pressure,it is found that the applied voltage,the gap distance,the electrode diameter,the gas flow rate,and the single-layer or the double-layer directly affect optical and electrical characteristics of the DBD.The discharge efficiency can be improved by effectively controlling the parameters of the experimental conditions.Therefore,it is necessary to study optical and electrical characteristics of the DBD,which has important theoretical significance for the dynamics of the DBD and industrial applications.