Research on microscopic process of 5mm air gap discharge at atmospheric pressure

In order to absolutely understand the microscopic process of discharge development at atmospheric pressure, the experiment of 5mm air gap discharge in the condition of rod-plate electrode is carried out, and not only the images of discharge process are recorded by intensification charge-coupled device, but also the discharge spectrum is captured. Furthermore, the hydrodynamic model is also adopted to reveal the microscopic mechanism of the 5mm air gap discharge. According to experimental results, electron temperature is estimated to be about 3.15eV. On the other hand, the simulation results show that the discharge process of the 5mm air gap could be divided into three stages: the electron avalanche stage, the streamer formation stage and streamer development stage according to the change of the peak value of the electron density.