Atlas-a facility for high energy density physics research at Los Alamos National Laboratory

Atlas is a facility designed to perform high energy-density experiments in support of weapon-physics and basic-research programs at Los Alamos. The capacitor bank design consists of a 36-MJ array of 600-kV Marx modules. The system is designed to deliver a peak current of 20-25 MA with a 2-3 /spl mu/s rise time. The capacitor bank is resistively damped to limit fault currents and capacitor voltage reversal. Both oil- and air-insulated Marx module designs are being evaluated. An experimental program for testing both prototype components and the air-insulated concept is currently underway. The capacitor bank design contains 300 closing switches. The primary candidate is a modified version of a Maxwell railgap switch originally designed for the DNA-ACE machines. An alternative candidate is a low-inductance surface-discharge switch. Because of the large number of switches in the system, individual switch prefire rates are required to be less than 10/sup -4/ to protect the high-value loads and targets. Experiments are underway to determine if switch-prefire probability can be reduced by increased capacitor charging rates. A pulse-charging system is described which is capable of charging the 36-MJ capacitor bank to full voltage in 40 milliseconds. This system would use the LANL 1430-MVA generator and a 50-MJ set of intermediate energy-storage inductors. Charging the capacitor bank with a large rectifier connected directly to the generator is another option, and would produce charging times in the 1-6 s range. Conventional rectifiers and grid power would be used for charging times >6 seconds.