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A series of pulsed power driven recent Kr gas-puff experiments on the Sandia National Laboratories Z machine have produced intense X-rays in the multi-keV photon energy range. Krypton spectra from Z pinch implosions can be used to analyze the presence and dynamics of the emitting regions, which could dominate the Kr K- and L-shell yields. This theoretical investigation of highly charged high atomic...
Substantial progress has been made in developing plasma radiation sources from Z-pinch implosions. University pulsed power machines provide a cost effective platform to study alternative mechanisms of producing x-rays in exploratory experiments that may provide guidance in search of further improvements on the larger machines. Radiation from puff-on-wire implosions were studied by Chuvatin et al....
(Mach2-TCRE is a two-dimensional (R-Z) radiation MHD Z-pinch simulation code with non-LTE population kinetics and radiation transport using ray tracing. The tabular collisional radiative equilibrium (CRE) based equation-of -state (EOS) model used in this code requires three table inputs: ion density, specific internal energy, and the effective escape probability in a strong radiating line, one from...
Advances in diagnostics at the refurbished Z facility at Sandia National Laboratories (SNL) now allow spatially and temporally resolved spectra to be obtained, with improved signal-to-noise ratios. Z-pinch simulation models have also improved, due both to substantial advances in the understanding of the underlying physics, and to the development of more detailed and accurate atomic databases. We will...
Large diameter (50-70 mm) wire array z pinches are fielded on the refurbished Z machine to generate 1-10 keV K-shell x-ray radiation. Imploding with velocities approaching 100 cm/μs, these loads create large dL/dt which generates a high voltage, stresses the convolute, and leads to current loss. High velocities are required to reach the few-keV electron temperatures required to strip moderate-atomic-number...
A series of Al/Mg nested wire array Z-pinch load experiments has been recently performed on the refurbished Z accelerator. The earlier comparison study of the results from ID and 2D radiation MHD simulations of the Sandia Z1907/1908 experiments [Y. K. Chong, et. al, APS09] has shown that, in addition to the substantial difference in the prediction capability of the ID and 2D models, the radiation...
A two-dimensional radiation MHD model that includes a self-consistent calculation for non-local thermodynamic equilibrium kinetics and ray trace based radiation transport1 is employed to simulate 65 mm diameter stainless steel double wire array Z machine experiments of 5.0 mg and 2.5 mg, respectively (shots Z1859 and Z1860). Temporal knowledge of the plasma internal energy, ion density, velocity,...
Summary form only given. Fast z-pinches produce intense K-shell radiation from wire arrays and for Cu arrays these photon energies can exceed 8 keV Experimental investigations of pinches on ZR using Cu arrays have already begun and more are planned for the near future. However to produce significant K-Shell emissions from moderately high atomic number plasmas such as Cu, they must be rapidly ionized...
Summary form only given. Copper wire arrays have previously been fielded in large diameter (up to 70 mm) nested configurations on the 20 MA Z machine, with average Cu K-shell (8.4 keV) yields of 20 kJ typical. More recently, Cu K-shell source development studies have been performed on the refurbished Z machine, which in initial commissioning shots has produced just over 20 MA current in these loads...
Summary form only given. Full understanding of the dynamics, population kinetics, and energy budget of a K-shell radiating Z-pinch remains a challenging problem in high energy density plasma physics. Recently, detailed axially-imaged spectroscopic measurements were performed on a Ne gas puff driven by the Weizmann generator (500 kA in 500 ns). The Gaussian line widths and measured energy input into...
Summary form only given. A two-dimensional radiation MHD model was recently developed and employed to investigate large diameter wire array Z-pinch experiments performed on the refurbished Z generator. This model incorporates into the Mach2 MHD code a self-consistent calculation for non-local thermodynamic equilibrium kinetics and ray trace based radiation transport. This level of detail is necessary...
We have developed a collisional-radiative spectroscopic model that combines the completeness of highly averaged Rydberg states models with the accuracy of detailed models for all important excited states. Our model includes an abundance of levels and atomic structure data as well as collisional and radiative processes including excitation, ionization, and recombination level couplings. This approach...
Summary form only given. K-shell X-rays have been studied with various materials at the 20-MA (pre-refurbished) Z accelerator. This paper presents results obtained for the ablation dynamics and stagnation physics of single and nested copper z-pinches with varying initial load diameters. Monochromatic imaging and shadowgraphy provide detailed information regarding the ablation of the wires and the...
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