Overview and Status of the Upgraded Z Pulsed Power Driver

The Z pulsed power driver at Sandia National Laboratories has been upgraded to deliver more energy to imploding plasma and magnetic pressure equation-of-state loads. The upgraded system has been tested with up to 25 MJ stored in the Marx generators, and with more than 26 MA delivered to a magnetic pressure load. Large, multi-module systems such as Z require high performance, highly accurate, and highly reliable energy storage, pulse compression and power flow systems. Each of thirty-six separate modules must provide a 3 TW pulse in 6.4 Omega water transmission lines. The modules deliver more than 250 kJ apiece to the common load. The goal for this system is temporal accuracy of the 100 ns rise time load current to be within plusmn1 ns. At the same time, the probability of a pre-fire of any of the approximately fourteen hundred high voltage, high current spark gap switches in the machine must be low. The competing requirements of low jitter and low prefire rate are addressed on Z by using strong triggering and optimized designs. Issues of high reliability are addressed by extensive calculations and testing. We will show the design goals and implementations, as well as results from the initial experiments on the machine. We will show the performance of the various subsystems, from the primary trigger generator that starts the high-voltage triggering process, through the pulse-forming system, to the vacuum insulator stack and the magnetically insulated transmission lines that deliver energy to the load.