Force at spark discharge in pin-to-plate gas discharge system

It was investigated whether the electrostatic force was generated at the spark discharge on a pin electrode in a pin-to-plate gas discharge system. Because it was not possible to measure the force directly at a short sparking period, three independent metcods were employed to evaluate the existence of the force indirectly. (1) Axial vibration was observed at the intermittent spark discharge for the softly supported pin electrode. The force was explicitly calculated in the case that the calculated vibration was well agreed with the measured. This experiment indicated that the force was almost 0 N at the spark discharge. The vibration was generated not by the force at the spark discharge but by alternative ionic wind at corona discharge. (2) A similar experiment was conducted whether the vibration magnitude depended on the spark current. The current at the spark discharge was varied by a circuit resistor. The experiment deduced that the force did not generated at the spark period and it was independent on the current. (3) Axial vibration could be observed when the voltage pattern that was common with that with the spark discharge was applied, if no force was applied to the pin electrode. To confirm it an experiment was conducted with two parallel-connected pin-to-plate gas discharge systems, one of which air gap was shorter than the other. The axial vibration of the longer air gap, in which the spark discharge did not take place, was observed and vibration also agreed quantitatively with calculated one. These three results suggested that no substantial force was generated at the spark discharge.