Monochromatic Soft X-Ray Self-Emission Imaging in Dense Z Pinches

The Z machine at Sandia National Laboratories drives 20 MA in 100 ns through a cylindrical array of fine wires which implodes due to the strong j × B force, generating up to 250 TW of soft x‐ray radiation when the z‐pinch plasma stagnates on axis. The copious broadband self‐emission makes the dynamics of the implosion well suited to diagnosis with soft x‐ray imaging and spectroscopy. A monochromatic self‐emission imaging instrument has recently been developed on Z which reflects pinhole images from a multilayer mirror onto a 1 ns gated microchannel plate detector. The multilayer can be designed to provide narrowband (∼10 eV) reflection in the 100–700 eV photon energy range, allowing observation of the soft emission from accreting mass as it assembles into a hot, dense plasma column on the array axis. In the present instrument configuration, data at 277 eV photon energy have been obtained for plasmas ranging from Al to W, and the z‐pinch implosion and stagnation will be discussed along with > 1 keV self‐em...