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Enhancement in x-ray emission from laser plasmas produced from an alloy of gold and copper (Au 0.43+Cu 0.57 atomic composition) has been observed in a narrow spectral region of 1.5–3.9Å. X-ray emission is observed to be as high as six to nine times as compared to pure copper and 1.5 to 1.8 times as compared to pure gold targets. In these experiments, a single pulse from a Nd:glass laser (λ=1.06μm) having an energy up to 2J and 500ps pulse duration was used to obtain a focused intensity of 1013–1014W∕cm2 on the targets. The results are explained on the basis of enhanced group Rosseland opacity (Rosseland mean over the spectral range under consideration) for the Au–Cu alloy target as compared to either of the pure targets.

A simple method of supersonic plasma jet production where the jet is formed in a cylindrical channel guiding the plasma generated from a laser-irradiated thin foil target is proposed and examined. High-Mach number ͑Ն10͒ plasma jets of parameters relevant to laboratory astrophysics applications using 120 J, 1.315 m, and 0.3 ns laser pulse for a thin CH foil irradiation are demonstrated. The method seems to be flexible in the production of jets of various compositions and hydrodynamic parameters and does not require high-energy lasers for the jet generation.

Acceleration of a thin (10 or 20μm) plastic foil by 120J, 0.438μm, 0.3ns laser pulse of intensity up to 1015W∕cm2 has been investigated. It is shown that the introducing a high-Z dopant to the foil causes an increase in the ablating plasma density, velocity, and collimation which, in turn, results in a remarkably higher kinetic energy and energy fluence of the flyer foil.

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