NIF power conditioning system testing at LLNL

Summary form only given. A fully integrated test facility for the National Ignition Facility (NIF) Power Conditioning System (PCS) was completed in August of 2000 at LLNL. The system consists of the computer control and data acquisition sub-system, a 24kV 2.2-MJ Main Energy Storage Module (MESM), Twenty 180ft lengths of high voltage transmission cable, and a standard NIF flashlamp load (the Frame Assembly Unit or FAU). The MESM can contain up to 24 (20 nominal) 300muF energy storage capacitors. Stainless steel inductive/resistive (9uh/0.026 ohms) damping elements limit fault currents in the event of a capacitor or main bus failure. A single spark-gap switches the entire bank output through ballast inductors to the output cables. Each cable has it own ballast inductor to insure current sharing, the values of the inductors are varied with cable length. The test facility can be fired once every ten minutes with a total peak output current of 580kA at pulse width of 400us. We will present in detail tests performed to demonstrate that the system meets all specifications for operational performance well as statistical data verifying stability and reliability.