Experimental Apparatus for Direct Observation of Anode Initiated Vacuum Surface Flashover

William Brooks, Texas Tech University

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Vacuum surface flashover imposes a limiting constraint on large-scale pulsed power machines. It is a weak spot in power flow from the primary pulse to experimental loads. Understanding of the subject is limited and has become a barrier to modernization and improvement of existing infrastructure. Modern designs employ a geometry which has been optimized for performance and machinability. Further understanding of the phenomena is needed to inform the path to improvement. For this reason, a new experimental apparatus for the study of vacuum surface flashover has been designed and constructed. Pulses of up to 500 kV have been delivered for tens of nanoseconds. Rise time are on the order of single to tens of nanoseconds for the typical pulse allowing anode-initiated flashover of six millimeter gapped samples to be reliably achieved with the need for an intentional flaw. The design of this device, its commissioning, and some experimental results will be presented with comparison to current theory.

Sandia National Laboratories is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.