Influence of Wall Charges on Discharge Characteristics of Surface Discharge

The discharge current and the inception voltage in a surface discharge device have been measured to investigate the influence of wall charges on the discharge characteristics in argon. The results show that the inception voltage decreases as the amplitude of the applied voltage U_p increases. However, the sum of the inception voltage and the applied voltage almost keeps constant when U_p is changed, due to the fact that the wall charges are generated in the discharge process. This phenomenon suggests that net electric field between the electrodes almost keeps constant when the amplitude of the applied voltage is changed. The electron temperature calculated by the intensity ratio of emitted spectral lines has been estimated to be less than 0.3eV and almost keeps constant under different amplitudes of the applied voltage. The result is consistent with nearly constant net field. The duty ratio of the discharge current increases as the amplitude of the applied voltage increases.