Conduction time/current limitation on the Defense Special Weapons Agency DECADE Module 1

The Defense Special Weapons Agency´s DECADE radiation effects simulator design consists of 16 separate pulsed power modules each driving individual bremsstrahlung diodes. DECADE is required to produce a dose in a near field test plane of 20 krad (Si) with 2:1 uniformity over 10000 cm/sup 2/, as well as meeting several other specifications. Each DECADE module utilizes a plasma opening switch (POS) in the final stage of pulse compression. DECADE Module-1 (DM 1), the first full scale module tested, is capable of delivering up to 1.8 MA in 300 ns to the POS. Power delivery to the load is dependent on the POS and load coupling performance. During testing the DMI performance level was found to be nearly a factor of two below that required to meet the DECADE dose specification. A DECADE Assessment Program was initiated to evaluate and assess the likelihood of achieving the original design specification based on the performance of a single module. The Assessment Program, with emphasis on diagnostics, was coordinated by scientists from Maxwell Technologies, the Naval Research Laboratory, and Primer/Physics International and included involvement by other collaborators throughout the pulsed power community. This paper describes the results of a study addressing the observed degradation in dose with increased POS conduction current and/or conduction time.