Structure of the Dense Plasma Focus: Part I: Numerical Calculations, X-Ray and Optical Measurements

Preliminary results of numerical calculations are presented. They are based upon the application of Potter's code to our particular DPF-geometry. The implosion phase, the radial oscillations of plasma, and the axial drift of constant-density profiles in the plasma column are studied. The electronic temperature is determined by detecting simultaneously the continuum X-ray radiation passing through different filters. By using a new diagnostic tool, which has recently been developed in Frascati, and consists of a channel multiplier array associated with a conventional image-converter camera. X-ray framing pictures with 10-ns exposure time are obtained. They allow an evaluation of the location and dimensions of the hot plasma. Correlations between neutron and X-ray emissions are discussed. The optical emission during the compression phases is recorded by an image-converter streak camera observing the axial region through a 100 μ slit parallel to the axis. In this way, the radial oscillations and the axial motion of the plasma are studied. A new diagnostic method is proposed. It allows simultaneous determination of both the electronic temperature and density by using time-resolved, relative, spectroscopic measurements on suitably chosen impurity lines. The characteristics of this method are described in this paper. (author)