Delay calculation of field-breakdown triggered vacuum switch

Triggered vacuum switch (TVS) is one of the important switch apparatuses in the fields of pulsed power system, due to its quick switch, rapid dielectric recovery, small volume, convenient trigger system, and simple structure, etc. A sample of field-breakdown TVS was fabricated and its turning-on experiments were done. Initial plasmas played an important role in the turning-on process of TVS, so the delay of TVS was tested, including wait time t₁ and collapse time t₂, and it could implicate the needed time of development of initial plasmas. From thermodynamics equations, a model of cathode spots heat conduction was set up. A formula deduced from the heat conduction model could calculate the delay of TVS. Calculated results of t₁ and t₂ were accordant with the tested results.