One-dimensional radiation-hydrodynamic scaling studies of imploding spherical plasma liners

One-dimensional radiation-hydrodynamic simulations are performed to develop insight into the scaling of stagnation pressure with initial conditions of an imploding spherical plasma shell or "liner." Simulations reveal the evolution of high-Mach-number (M), annular, spherical plasma flows during convergence, stagnation, shock formation, and disassembly, and indicate that cm-and mu s-scale plasmas with peak pressures near 1 Mbar can be generated by liners with initial kinetic energy of several hundred kilo-joules. It is shown that radiation transport and thermal conduction must be included to avoid non-physical plasma temperatures at the origin which artificially limit liner convergence and, thus, the peak stagnation pressure. Scalings of the stagnated plasma lifetime (tau(stag)) and average stagnation pressure (P-stag, the pressure at the origin, averaged over tau(stag)) are determined by evaluating a wide range of liner initial conditions. For high-M flows, tau(stag) similar to Delta R/v(0), where Delta R and v(0) are the initial liner thickness and velocity, respectively. Furthermore, for argon liners, P-stag scales approximately as v(0)(15/4) over a wide range of initial densities (n(0)) and as n(0)(1/2) over a wide range of v(0). The approximate scaling P-stag similar to M-3/2 is also found for a wide range of liner-plasma initial conditions. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3610374]