Analysis of implosion and stagnation of stainless steel wire array z-pinches at 18MA on the Z generator

Summary form only given.We present detailed analysis of the implosion dynamics and stagnation of a Stainless Steel wire array z-pinch on the Z generator. Z2011 was a 0.68mg/cm, 70mm on 35mm nested wire array. In this presentation we use the complete set of data available for this shot to discuss in detail the implosion dynamics and conditions in the final pinch. Time resolved soft x-ray (hv ~277eV and >;5 keV) self emission imaging is used to diagnose the global dynamics of the implosion phase of the wire array. The implosion trajectory from this diagnostic is compared to spectral measurements of the L-shell emission of the constituent materials, where Doppler line splitting was observed and used to estimate implosion velocity. Radially resolved, time resolved spectral data collected during the stagnation of the pinch plasma onto the axis will be presented. Optically thin lines are used to provide an upper estimate of the ion temperature, and to follow the history of the ion temperature in time. Ion temperatures appear to be lower than ~100keV, and a decrease in ion temperature is seen over the ~2ns duration of the x-ray pulse. MHD simulations of this wire array will also be presented, including various reconstructed diagnostics such as time resolved soft x-ray and >;1keV self emission images, and emissivity weighted simulated line-shapes. We will discuss how the spectral line widths can be affected by the temperature and dynamics of the imploding plasma. We will also compare the experimental data and simulations of Z2011 to other similar Stainless Steel shots.