Self-healing pulse capacitors for the National Ignition Facility (NIF)

Approximately 4000 capacitors, each storing 83.5 kJ of energy, will be required for the United States Department of Energy National Ignition Facility (NIF), being built at Lawrence Livermore National Laboratory (LLNL). To achieve the required system reliability lifetime, and cost goals, the capacitors were specified to be of the self-healing, metallized electrode type of construction. Maxwell Energy Products has previously delivered a number of banks of self-healing capacitors, including the 52 MJ bank at the US Army ARDEC facility at Picatinny Arsenal, NJ. Development of capacitors specifically for NIF began several years ago and continues today at Maxwell, with the primary goal of reducing the manufacturing cost. In support of this effort, LLNL has procured prototypes and life tested a number of our designs over the past three years. This paper reviews the development of NIF capacitors at Maxwell, focussing on the lifetime performance of different designs during the development. This work has resulted in Maxwell Type CM capacitor designs, whose demonstrated lifetime capability has far exceeded the 20000 shot NIF requirement, having energy densities as high as 0.84 J/cc.