New exact MHD solutions describing the stagnating Z-pinch plasma

Summary form only given. Recent 3D RMHD simulations and experiments have demonstrated that axially and azimuthally averaged dynamics of a strongly radiating stagnated Z-pinch column resembles a self-similar, cylindrically symmetric motion. The cold, rapidly imploding incident plasma transforms into the hot stagnated plasma when it gets heated and compressed in the diverging shock wave that propagates from the pinch axis. The simplest analytical solution describing such flow was given by Noh and found to be surprisingly close to the observations and simulation results,. Here we discuss generalizations of the classical Noh's solution, which take into account the non-uniform density and velocity profiles in the incident plasma, as well as the presence of axial current and azimuthal magnetic field in it. These new solutions are compared with the data from and with exact solutions of different types, like those describing shock-free compression and expansion to elucidate the relative roles of shock and adiabatic compression and heating in shaping the radiating Z-pinch column. These closed form solutions are also useful for verification tests of MHD codes.