Experimental Study on Multigap Multichannel Gas Spark Closing Switch for LTD

In this paper, a multigap multichannel gas spark closing switch (MMCS) has been modified to improve the synchronous closing characteristics of ten switches designed for linear transformer driver (LTD). Convexo-convex discal electrodes have been used instead of the plane toroidal electrodes to improve the electric field across the gaps. A new endo-grooved plane bracing structure has been designed for fixing the electrodes instead of the small ball anchoring method to ensure the length of the gap uniformity. In order to observe the discharge process of the MMCS, the transparent Incite insulation chambers instead of the nylon ones have been used. A test circuit comprising a single discharge circuit called LTD brick has been established to investigate the self-breakdown and triggered breakdown characteristics of ten switches. The results show that when switches are filled with pure nitrogen of 0.14 MPa and charged to +/- 60 kV, the synchronous discharge of ten MMCSs has output a current pulse with an amplitude of about 100 kA and a rise time of 100 ns.