Study of hard x-ray emission from high energy density plasmas

Abstract

Summary form only given: The study of characteristics of hard x-rays and generation of electron beams is very important for high energy density physics (HEDP).The illustration of such a study is performed by using Z-pinch plasma. Specifically, we are studying implosions of different types wire array loads and materials that produce hard X-rays (HXRs) and e-beams. We analyze characteristics of HXR produced by in multi-planar wire arrays such as single planar, double planar, triple planar, cross planar, and compact cylindrical wire arrays. The study of HED plasma from such elements as Al, Cu, Mo, W is important for HEDP. Data from spatially resolved time-integrated and spatially integrated time- gated x-ray spectra recorded by LiF spectrometers, and pinhole images has been analyzed to study spatial distribution of HXR emission with different load and different material. The dependence of the HXR yield and power on the wire material, and geometry of the load is determined. The HXR yield increases with the rise of atomic number of material for all loads. For W plasma, the intensity of cold L-shell spectra (1.39-1.54 Aring) correlates with corresponding amplitude of HXR peaks which may suggest the evidence of generation of electron beams. The HXR yield per unit length increases with the rise of load height (anode- cathode gap). The presence of aluminum wires as a tracer to main material like Cu, Mo, W in combined wire arrays decreases HXR yield. It is found that HXRs are generated from different plasma regions by the interaction of e-beam with cooler trailing mass, material of anode and due to thermal radiation from plasma bright spots.