Cylindrical Liner Z-pinch Experiments on MAGPIE

The formation of plasma in thin-walled metal tube (liner) experiments on the MAGPIE generator (1.4 MA, 240 ns rise) was investigated using axial and side-on laser probing and self-emission imaging. Liners with a wall thickness comparable to the initial current skin depth allow magnetic field diffusion through the wall, driving a cylindrically converging plasma flow from the inner surface at a speed of approximately 100 km s$^{-1}$. Initial flow has good azimuthal symmetry, with radial striations appearing later. The growth and azimuthal correlation of plasma instabilities on the outer liner surface is also observed, in conditions where no bulk motion of the liner occurs. Finally, the effect upon ablation dynamics of filling the interior of the liner with gas prior to application of the current pulse is presented.