  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 (Pstag, 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 L0/v0,
where L0 and v0 are the initial liner thickness and velocity, respectively.
Furthermore, for argon liners, Pstag scales approximately as v0^(15/4) over a
wide range of initial densities (n0), and as n0^(1/2) over a wide range of v0.
The approximate scaling Pstag ~ M 3/2 is also found for a wide range of
liner-plasma initial conditions.
