Atlas-a new pulsed power tool at Los Alamos National Laboratory

The Atlas pulsed power driver has recently been commissioned at Los Alamos National Laboratory. This paper provides an overview of the ATLAS facility, its initial experimental program and plans for the future. The reader desiring more detailed information is referred to papers in this conference by Keinigs et al. on materials studies, Cochrane et al. on machine performance and Ballard et al. on fabrication and assembly. Atlas is a high current generator capable of driving 30 megamps through a low-inductance load. It has been designed to require minimal maintenance, provide excellent diagnostic access, and rapid turnaround. Its capacitor bank stores 23.5 megajoules in a four-stage Marx configuration which erects to 240 kV at maximum charge. It has a quarter-cycle time of 4.5 microseconds. It will typically drive cylindrical aluminum liners in a Z-pinch configuration to velocities up to 10 mm/usec while maintaining the inner surface in the solid state. Diagnostic access includes 360/spl deg/ of radial view as well as axial views from above and below. The photograph shows the circle of tanks containing capacitor banks, the diagnostic platform and load area. Atlas construction began in 1996 and high-current acceptance tests were completed in December of 2000. Initial shots include liner characterization shots using a target design similar to NTLX experiments (see several papers by Turchi et al., this meeting). These will be followed by experiments studying hydro features, useful for validating hydrodynamic algorithms used in weapons computer codes. DOE plans to relocate the Atlas generator to the Nevada Test Site as early as 2002, where it will continue its experimental program supporting the Stockpile Stewardship program and other users.

I. Machine Capabilities

The Atlas pulsed power generator provides the largest current pulses, 30 megamps, of any fast capacitor bank in the world. When driving a low-inductance load, the current rises to its peak value in 4.5 microseconds. It is designed to drive solid metal liners at implosion velocities exceeding 10 km/sec while maintaining an unmelted inner surface. The Atlas capacitor bank stores 23.5 megajoules with a peak voltage of 240 kV. It has an overal system inductance of 18 nH with a typical load configuration. Figure 1. The Atlas generator consists of twelve capacitor bank tanks surrounding a central target chamber.