Study of Z-pinch X-ray emission in the implosion of fiber arrays at the angara-5-1 facility

Abstract

The present study describes the data on the current implosion of arrays made of kapron fibers coated with layers of metals: Al, In, Sn, Bi. Experimental data on the energy and pulse power of soft X-ray radiation (SXR) in the axial and radial directions in the energy range 0.02–2 keV were obtained by two sets of XRD detectors [1]. Spectral characteristics of the SXR source in a Z-pinch implosion of kapron fiber arrays were obtained using a grazing incidence diffraction spectrometer (GIS) in the radial direction with spatial resolution along the radius of the array. It is shown that the presence of kapron fiber matter defines the characteristics of SXR emitted by a Z-pinch in the radial and axial directions. A distinctive feature of the time profiles of XRD signals, which measure the power of SXR in the axial direction, is the presence of the second peak, which is strongly suppressed in the radial direction. It was found that power, total energy and emission spectra depend on the amount of metal-coated fibers and the mass of the layer of metal deposited on them, but do not depend on the characteristics of the material: its density, atomic number, etc. Frames of X-ray images show that the Z-pinches obtained with metal-coated kapron fiber implosion are characterized by increased stability and a lower growth rate of MHD perturbations compared to wire arrays. Slower intensity of plasma production from kapron fibers [2] leads to the fact that the plasma formed in the fiber periphery out of its material forms a layer which acts as a hohlraum wall, locking in the SXR of the Z-pinch formed during the implosion of the material of the deposited layer. It is shown that the overlap of the anode aperture doubles emission energy in the radial direction.