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The results of the experiments on Z-pinch produced from wire arrays performed on the facility Angara-5-1 are presented. The models of liner implosion, i.e. prolonged plasma production have found their confirmation. Estimation based on our experimental data show that W wire cores are heterogeneous. The velocity of core expansion is determined by energy deposited at the first nanoseconds after current start. The effect of the inner array on the current distribution in the region between the arrays has been revealed. The «lost mass » was measured at initial radius of array at the moment of X-ray pulse maximum. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

In the physics of the wire array implosion the amount of the substance left on the periphery of the initial wire array at the moment of final liner implosion is an essential factor. Estimates show that plasma with a small mass fraction (a few percent of the initial wire array mass) may shunt an appreciable current fraction which can result in changing output characteristics of implosion. The given paper reports the investigation into the plasma density distribution on the periphery of the initial wire array near the moment of final implosion. [ABSTRACT FROM PUBLISHER]

The backlighting method on the base of X-pinch is developed last years for radiography of current driven wire array implosion. The simple and nested arrays were investigated on installation ≪Angara-5-1≫. The experimental geometries and outcomes received at probing current — driven multiwire liners at the Angara-5-1 facility are presented below. [ABSTRACT FROM PUBLISHER]

Usage of fast Z-pinch for generation of shock wave in the thick target (100÷400 µm, ∅4 mm) from different metals (Pb, Mo, Ta, W) has shown small size of spot (0.6÷1.5 mm) at shock wave output on back side of the target. The target was placed in anode hole. The size of spot did not depend on distance of the target to anode. At excess of some distance (3÷4 mm) spot disappeared. The purpose of given activity was to find out, which components of axial energy flux through anode hole are responsible for such character of shock wave. [ABSTRACT FROM PUBLISHER]

The data on measurements of magnetic fields in plasma at current implosion of multi wire cylindrical liners at the Angara-5-1 facility are presented. The measurements were performed at a current of up to 4 MA in the load and a SXR power of up to 3 TW. The compression of an axial magnetic flux with the plasma produced by a multi wire liner is investigated. A compression model for such flux is suggested in the frames of the concept of the prolonged plasma production. Radial and azimuthal structures of the current plasma are also studied. It has been shown that in the process of the plasma production a magnetic field is frozen-in to the plasma. The liner volume is filled with the plasma impregnated with current and magnetic field. [ABSTRACT FROM PUBLISHER]

Measurements of spatial shape of wire array produced Z-pinch is described. Nonsymmetry of the cathode and anode regions of pinch was observed. According to different spectra of X-ray emission emissive aria separates on two zones. For a single array an analogue of a ≪zipper effect≫ is observed: a hot zone appears at the cathode and expands towards the anode. [ABSTRACT FROM PUBLISHER]

Brief review of our recent results concerning prolonged plasma production (P³) in multiwires arrays and its influence on their dynamics in pulse power facilities is presented. P³ means that owing to overheating effects hot plasma with high conductivity is being produced from the relatively cold material almost during the whole period of current rising. P³ results in formation of a plasma shell with a low aspect ratio and without any skin effect. It means that magnetic flux and electric current are distributed more or less uniformly along the shell and there is no magnetic piston. The latter fact is responsible for the more stable implosion of the plasma. P³ is unavoidable effect for initially cold liners of all types in pulse power facilities, and it is useful for production of high power X-ray pulses with multiwires arrays because the process of P³ leading to more stable implosion is well controlled in this case due to well defined periodic structure of the array. Theoretical evaluation of rate of plasma production is obtained, and it is compared with experiments. Simple simulation of plasma dynamics during implosion of multiwire arrays with P³ is presented. Combining of such simulation with probe magnetic measurements inside cylindrical liners we obtain a certain information about dependence of the plasma production rate on time and about characteristics of depletion of plasma source. It appears that process of the depletion may be rather gradual, so that some amount of plasma is being placed at initial array position even till the moment of X-ray pulse maximum. It may lead to partial shunting of electric current and to some depression of X-ray pulse intensity. These results discover new opportunities to control plasma implosion and X-ray pulse parameters. [ABSTRACT FROM AUTHOR]

The study of the wire array implosion on installation Angara-5-1 is devoted. Magnetic probes and the x-ray backlighting technique were used to investigate a current and mass distribution during the implosion. The experimental data confirm the concept of prolonged plasma production: the long time of implosion the hot plasma flows from dense fixed wire cores and is accelerated by the Lorentz force to the array center together with frozen magnetic field. [ABSTRACT FROM AUTHOR]

Data on the energy, power and spectra composition of the soft x-ray pulse of powerful Z-pinch plasmas in the axial and radial directions in the photon energy range of 0.02 - 2 keV are presented. The data are obtained from the analysis of experimental results on the implosion of cylindrical arrays with a diameter of 1.2 cm and a height of 1.6 cm of tungsten wires diameter of 6 μm, the linear mass of 220 μg/cm at a current in the range of 2.2 - 3.5 MA at the Angara-5-1 facility. [ABSTRACT FROM AUTHOR]