Modeling of radiative properties of the wire array Z-pinches

Recent experiments show that the wire-array z-pinch plasmas are strongly inhomogeneous at small scales. The inhomogeneities are not shot-to-shot reproducible while the arrays provide extremely reproducible x-ray pulses and generate mega-joules of radiation at implosion. This is possible if small-scale structures are averaged in the implosion dynamics and if the energy balance and radiation production are mainly determined by the macroscopic, space-averaged plasma properties. We suggest that the basic physics of radiating wire array implosions could be modeled within a quasi-1D large-scale description. We show that such a quasi-1D hydro model reproduces basic radiative properties of the wire-array z-pinches if the Spitzer resistivity is enhanced by a factor, proportional to β², where β = ω_eτ _e is the Hall parameter. It becomes possible to explain the radiation pulse shapes and high experimental efficiency of magnetic energy conversion into radiation in the most powerful laboratory x-ray sources. Our results also reproduce some recently discovered properties of these x-ray sources, such as trailing mass during the implosion and radiation beginning before arrival of the entire imploding mass onto the axis.