Path integral approach to no-Coriolis approximation in heavy-ion collisions

We use the two time influence functional method of the path integral approach in order to reduce the dimension of the coupled-channels equations for heavy-ion reactions based on the no-Coriolis approximation. Our method is superior to other methods in that it easily enables us to study the cases where the initial spin of the colliding particle is not zero. It can also be easily applied to the cases where the internal degrees of freedom are not necessarily collective coordinates. We also clarify the underlying assumptions in our approach.Comment: 11 pages, Latex, Phys. Rev. C in pres

Radiation environments produced by plasma Z-pinch stagnation on central targets

A goal of modern pulsed-power technology is the development of an intense, megajoule level source of soft x-rays for use in high-energy density physics experiments. Since 1980 experimental facilities, theoretical concepts, computational tools, and diagnostics have been developed that place pulsed-power at the threshold of performing experiments of great interest to the applied physics community. In this paper the ``Flying Radiation Case`` approach will be presented and its predicted performance on Sandia National Laboratory`s Z-Machine [M.K. Matzen, Phys. Plasmas 4, 1519 (1997)] is described. The effects of instability growth in the plasma during the implosion, its reassembly on a central cushion, and the plasma interactions with shaped electrodes are considered

One-and-Two-Dimensional Simulations of Liner Performance at Atlas Parameters

The authors report results of one-and-two-dimensional MHD simulations of an imploding heavy liner in Z-pinch geometry. The driving current has a pulse shape and peak current characteristic of the Atlas pulsed-power facility being constructed at Los Alamos National Laboratory. One-dimensional simulations of heavy composite liners driven by 30 MA currents can achieve velocities on the order of 14 km/sec. Used to impact a tungsten target, the liner produces shock pressures of approximately fourteen megabars. The first 2-D simulations of imploding liners driven at Atlas current parameters are also described. These simulations have focused on the interaction of the liner with the glide planes, and the effect of realistic surface perturbations on the dynamics of the pinch. It is found that the former interaction does not seriously affect the inner liner surface. Results from the second problem indicate that a surface perturbation having amplitude as small as 0.2 {micro}m can have a significant effect on the implosion dynamics