Su Guoqiang

This paper investigates the influence of gas pressure and ambience on surface barrier discharge by surface charge measurement device based on Pockels effect. The results show that, with decreasing of gas pressure, the length and radius of surface charge distribution have increased, but the charge densities have decreased. The product of pressure and diameter of diffuse discharge region in positive surface discharge is nearly constant. The value is about 260(kPa·mm) The surface charge appears diffusely when pd is smaller than 260(kPa·mm), surface charge appears diffusely, and while pd is larger than that value, they gradually develop to filamentous pattern. Compared surface charge distributions in air and nitrogen gas, it shows that positive discharges present more branches in nitrogen gas.