A polarized light interferometer, suitable for the high-speed photography of microscopic objects in laser fusion experiments, is described. Based on a Wollaston prism as beam splitter, its main advantages are its relative simplicity, the absence of alignment and stability problems, and the extended spectral range down to 0.18 mum wavelength. The interferometer has been successfully applied in CO(2) and neodymium laser plasma interaction studies with laser illumination at 0.694 mum (ruby laser) and 0.265 mum (4th harmonic of the Nd(3+) laser) wavelength.

The multicharged plasma implosion stability with respect to Rayleigh–Taylor axial modes and its modification by the electromagnetic field diffusion and radiation cooling is considered. The exterior and the interior parts of an imploded plasma shell are examined and stability and conditions for magnetohydrodynamic Rayleigh–Taylor instability are obtained. The external surface is always unstable. The interior instability appears, as a rule, to be under a significant degree of compression near the final stage of implosion. Theoretical results and numerical simulations using the two-dimensional ZETA code are [R. Benattar et al., 4th International Conference on Dense Z pinches, Vancouver (American Institute of Physics, Woodbury, 1997), p. 211] compared. The modeling of the implosion of wire arrays and nested tungsten wire arrays on the Z generator by the two-dimensional magnetohydrodynamic code ZETA, including radiation transport with local thermodynamic equilibrium (LTE)—nonequilibrium (non-LTE) approximation, is performed in order to study the influence of instability level on high-Z plasma radiation and to reproduce the experimental results. It is shown that it is possible to fit the experimental results if a 10% level of initial mass perturbation of the tungsten wire arrays is imposed. The dynamics of the implosion and the development of Rayleigh–Taylor instability are discussed. The plasma of the Z pinch is shown to be in a non-LTE regime.

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