A Marx Generator Diagnostic: Time-Resolved, High Bandwidth Spark-Gap Firing Order Measurement Using Optic Sensors

Increasing demands of the Nevada Test Site´s Stockpile Stewardship initiative require new approaches for designing brighter, highly energetic, efficient pulsed power X-ray sources. Marx generators are common devices often used for such pulsed power and x-ray source applications. One particular design challenge for these devices is to develop accurate circuit models that simulate and predict the Marx´s performance and to subsequently validate these models experimentally. An accurate measurement of the spark-gap firing order, with sub nanosecond resolution, is necessary for validation of the circuit model and of Marx generator operation. In this paper, a novel technique is presented which successfully applied fiber-optic probes and high bandwidth, streak camera recording to measure the relative closure time for each switch within a multi-stage Marx generator. Various output signals of the Marx generator are compared with the circuit model´s output for several shots with different spark-gap firing sequences.