SaTPro: the system assessment test program for ZR

In the mid-90's, breakthroughs were achieved at Sandia with z-pinches for high energy density physics on the Saturn machine. These initial tests led to the modification of the PBFA II machine to provide high currents rather than the high voltage it was initially designed for. The success of z-pinch for high energy density physics experiments insured a new mission for the converted accelerator, known as Z since 1997. Z now provides a unique capability to a number of basic science communities and has expanded its mission to include radiation effects research, inertial confinement fusion and material properties research. To achieve continued success, the physics community has requested higher peak current, better precision and pulse shaping versatility be incorporated into the refurbishment of the Z machine, known as ZR. In addition to the performance specification for ZR of a peak current of 26 MA with an implosion time of 100 ns, the machine also has a reliability specification to achieve 400 shots per year. While changes to the basic architecture of the Z machine are minor, the vast majority of its components have been redesigned. Moreover the increase in peak current from its present 18 MA to ZR's peak current of 26 MA at nominal operating parameters requires significantly higher voltages. These higher voltages, along with the reliability requirement, mandate a system assessment be performed to insure the requirements have been met. This paper will describe the System Assessment Test Program (SATPro) for the ZR project and report on the results

I. Introduction

ZR is a refurbished (R) version of Z aiming to improve its overall performance reliability, precision, pulse shape tailoring and reproducibility. Z, the largest pulsed power machine at Sandia, began in December 1985 as the Particle Beam Fusion Accelerator II (PBF A II). PBF A II(ref) was modified in 1996 to a z-pinch driver by incorporating a high-current (18MA, 2.5MV) configuration in the inner load section, Following its remarkable success as z-pinch driver, PBF A II was renamed Z in 1997. Currently Z fires approximately 180 shots a year with a peak load current of 18 MA into a standard z-pinch load. The maximum z-pinch output achieved to date is 1.6MJ, 170T\V radiated energy and power from a single 4-cm diameter, 2-cm tall array, and 215 e V temperature from a dynamic hohlraum. In recent years. Z has evolved from a research machine to a user facility. To accommodate user demands, ZR will enable 400 shots per year operating in double shifts. In addition to the z pinch operation, ZR will provide a pulse shaping flexibility extending from 100 ns to 300 ns for equation of state (EOS) and isentropic compression experiments (ICE). To achieve these new programmatic requirements, ZR will incorporate substantial upgrades and modifications to the Marx generators, intermediate store capacitors, gas and water switches) water transmission lines and the laser triggering system.