On the dynamics and stability of imploding wire arrays

Abstract
The experimental evidence made in SANDIA that the use of a large numbers of wires in the wire-array load enables to generate very high X-ray power stimulates to reconsider stability of the wire array implosion. Z-pinch implosions of cylindrical arrays of parallel wires driven by the magnetic forces generated by currents through the wires are studied. Growth rates of the instabilities are calculated and complete classification of possible instability modes is presented. For the relatively small number of wires, the wire arrays tend to develop a helical structure due to growth of the tangential modes of perturbations. Such a helical structure causes the increase of the load inductance and this can explain the discrepancy between the observed X-ray energy radiation and the kinetic energy of the imploding array calculated in 1D MHD model.