Refurbishment and enhancement of the saturn accelerator

The Saturn accelerator was commissioned in 1987 as a 5.4 MJ, 2.7 MV flash x-ray machine that delivers 750 kJ at 2.1 MV to a three-ring diode with peak power of 25 TW and FWHM pulse width of 40 ns.¹ The machine has also been extensively used for wire-array z-pinch experiments² with currents up to 8 MA, primarily prior to the startup of the Z accelerator. In the last few years the machine has not been fully used, and has not been fully maintained. But recently there has been interest in using it more regularly for x-ray testing of components. Therefore, a project has been initiated to refurbish the machine with emphasis on achieving better repeatability. This effort has involved rebuilding each of the 36 pulsed power lines, including Marx banks, 3 MV gas switches and trigger system, and water switches. In addition, there was considerable wear and mechanical misalignment in high-current joints in the vacuum magnetically-insulated transmission lines that has been corrected. Furthermore, timing and calibration of diagnostic monitors has been improved. In doing initial testing of the refurbished modules we realized that it is possible to transmit much more energy to the load than has been done regularly in the past by adjusting gas switch timing. This modification can increase downstream voltage by more than 50%. In this paper, along with describing the status of the machine refurbishment, we will describe tests done with this modification, its implications for other components in the machine, and expected improvement of load performance.