Experimental study of implosion dynamics of multi-material nested wire-arrays on S-300 pulsed power generator

On 'S-300' generator (700 kV, 4 MA, 70 ns) at the Kurchatov Institute, the experimental studies with multi-material wire array units are carried on aimed at creating the powerful X-ray source. The development of new diagnostic methods would definitely contribute to attain new data, which could help in explanation of X-ray emission mechanism of imploding multi-wire arrays that has not well understood yet. The experimental study of soft X-ray emission of different wire sets, different in both mass and composition, has been carried on in the same geometry. One of the purposes of these experiments was investigation of the wire array chemical composition influence on the implosion dynamics and stability. Study of the nested (cascade) liner dynamics shows that the minimal liner radius at the stagnation moment of time (2r ∼ 3 - 3.5 mm) recorded in the visible range by the streak camera fairly coincides with the outer diameter of the inner tungsten array of 4 mm. The same size is shown by the integral pinhole pictures obtained in the SXR range, without a filter. Unlike all these pictures, images obtained in the range E > 2 keV demonstrate the resulting state of Z-pinch in the form of a thin (∼ 0.2 mm) twisting filament. In addition, small space scales are typical of the liner pictures taken in the range of He- and H-like aluminum ions by means of a spectrograph. Thus, one may conclude that Al plasma of the outer liner passes into the inner space of the almost immovable W array where becomes trapped and compressed by the magnetic field. (author)