Design and simulation of stabilized Z-pinch loads with tailored density profiles

Summary form only given. We discuss the design of structured Z-pinch loads capable of mitigating the detrimental effect of Rayleigh-Taylor (RT) instability on the performance of fast Z-pinch devices used as plasma radiation sources. We demonstrate that using a structured gaseous load with a radial density profile specifically tailored for a given current wave form, it is possible to delay the onset of the RT instability development for as long as it takes for a shock wave to propagate through the load. Suppression of the RT instability is due to inverted acceleration of the interface between magnetic field and the plasma. Once the acceleration is inverted, perturbations are shown to oscillate rather than to grow exponentially. Our simulation results indicate the possibility of high-quality implosions producing significant Ar K-shell yield from initial radii in the range between 4 and 8 cm, with current pulse duration of 250 ns and longer. The stabilizing effects of current pulse shape (the higher the current rise rate, the better), of the axial (the hourglass effect) and the azimuthal (current switching) density tailoring will be also discussed.