An Experimental Investigation on Initial Plasma Characteristics of Triggered Vacuum Switch

The trigger characteristics of triggered vacuum switch are significantly influenced by initial plasma. An RC charge collector is designed based on the frequency spectrum characteristics of the initial plasma current, and the emission charge characteristics of the initial plasma are analyzed. The experimental results indicate the following: The RC charge collector is suitable to collect the charge of the initial plasma at R = 5 Ω and C = 300 nF, the charge of the initial plasma includes electrons and ions, the electrons are slightly more than the ions, the charge of the initial plasma increases linearly at the beginning with the increment of the charging voltage of the trigger circuit and the trigger current and then ascends gradually to a plateau under a gap space of 4 mm, and the charge of the initial plasma exponentially decreases with the increment of the gap space below 4 mm and then tardily drops to a stable value with the gap space continuingly increasing.