Numerical models of pressure pulse generation by imploding metal liners

The authors describe numerical calculations of pressure pulse generation using imploding liners. Liners are metal cylinders that are magnetically compressed by an intense axial current flow from a high-power pulse generator. The simulations cover the acceleration of the liner, collision with an internal diagnostic target, followed by compression and shock wave heating of the target. With the projected current waveform of the Atlas capacitor bank (in development at Los Alamos National Laboratory), initial results suggest that it may be possible to achieve pressures exceeding 3000 Gpa (30 Mbar) in a 4 mm diameter sample over an interval of 100-200 ns. The simulations were carried out with Crunch, a new one-dimensional hydrodynamics package for advanced personal computers. The program uses finite-element techniques to solve the coupled problems of hydrodynamics and magnetic diffusion. Crunch fully supports loading and interpolating Sesame equation-of-state tables. The program exhibits excellent stability, even for collisions between material shells and shock convergence on axis.