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Implosion dynamics and spectroscopy of X-pinches and wire arrays with doped Al wires on the UNR 1MA Z-pinch generator

AIP Conference Proceedings

Safronova, Alla; Kantsyrev, Victor; Esaulov, Audrey; Fedin, Dmitry; Ouart, Nicholas; Yilmaz, Fatih; Osborne, Glenn; Nalajala, Vidya; Pokala, Shivaji; Shrestha, Ishor; Astanovitsky, Alexey; Batie, Steve; Legalloudec, Bruno; Cowan, Tom; Jones, Brent M.; Coverdale, Christine A.; Deeney, Christopher D.; Lepell, David; Gradel, Josh

The study of implosion dynamics and spectroscopy of X-pinches and wire arrays with Al wires alloyed or coated with other near-Z or higher-Z materials is discussed. In particular, X-pinches from two combined Al 5056 and Mo wires and composed from four identical Al 5056 (5%Mg) wires and Cu clad Al (90% Al and 10%Cu) are studied. In addition, wire arrays with Alumel wires (95% Ni and 5% Al) and with Al 5056 wires (uncoated) and coated with 5% NaF are investigated. Spatially-resolved and integrated x-ray spectral data and time integrated and time-gated pinhole x-ray images accumulated in these X-pinch and wire array experiments on the UNR 1MA Zebra generator are analyzed. Modeling of K-shell radiation from Mg provides K-shell plasma parameters for all Al 5056 wire experiments, whereas modeling of L-shell radiation from Ni, Cu, and Mo provide parameters for L-shell plasmas. The importance of using different materials or dopants for understanding of implosion dynamics of different wire materials is illustrated. © 2006 American Institute of Physics.

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TYPE Conference YEAR 2006
ScopusOSTI

Seeded perturbations in wire array Z-Pinches

Jones, Brent M.; Deeney, Christopher D.; Mckenney, John M.; Garasi, Christopher J.; Mehlhorn, Thomas A.; Robinson, Allen C.; Coverdale, Christine A.

Controlled seeding of perturbations is employed to study the evolution of wire array z-pinch implosion instabilities which strongly impact x-ray production when the 3D plasma stagnates on axis. Wires modulated in radius exhibit locally enhanced magnetic field and imploding bubble formation at discontinuities in wire radius due to the perturbed current path. Wires coated with localized spectroscopic dopants are used to track turbulent material flow. Experiments and MHD modeling offer insight into the behavior of z-pinch instabilities.

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TYPE Conference YEAR 2005
OSTI

Dynamics of copper wire arrays at 1 MA and 20 MA

Coverdale, Christine A.; Jones, Brent M.; Deeney, Christopher D.

Experiments to study the implosion dynamics and radiation characteristics of copper z-pinches have been fielded at the 1 MA Zebra facility and the 20 MA Z facility. The impact of initial load mass, initial load diameter, and nesting of wire arrays on the precursor and the stagnated plasma has been evaluated through spectroscopy, shadowgraphy, and fluence measurements. Plasma parameters extracted from modeling of the time-integrated L-shell spectra indicate the presence of more than one plasma source contributing to the radiation, likely due to non-uniform hot spot x-ray emission or temporal gradients.

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TYPE Conference YEAR 2005
OSTI

Hybrid simulations of Z-Pinches in support of wire array implosion experiments at NTF

Coverdale, Christine A.; Jones, Brent M.; Deeney, Christopher D.

Three-dimensional hybrid simulation of a plasma current-carrying column reveal two different regimes of sausage and kink instability development. In the first regime, with small Hall parameter, development of instabilities leads to the appearance of large-scale axial perturbations and eventually to bending of the plasma column. In the second regime, with a four-times-larger Hall parameter, small-scale perturbations dominate and no bending of the plasma column is observed. Simulation results are compared with laser probing experimental data obtained during wire array implosions on the Zebra pulse power generator at the Nevada Terawatt Facility.

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TYPE Conference YEAR 2005
OSTI

Thermonuclear and beam fusion in deuterium Z-pinch implosions : theory and modeling

Deeney, Christopher D.; Ruiz, Carlos L.; Coverdale, Christine A.

The conclusions of this report are: (1) 1D and 2D RMHD simulations indicate feasibility of producing high thermonuclear neutron yields in deuterium and DT gas-puff Z-pinches -- (a) Z 1.7 x 10{sup 13} DD neutrons at 70 kV, 13 MA (Z1384); (b) (3 to 6) x 10{sup 14} at 90 kV, 17 MA (Z1422); (c) Predicted for ZR 2 x 10{sup 15} DD and 6 x 10{sup 16} DT neutrons; (2) Theory and modeling issues -- collisionless ions, nonthermal ions; (3) Experimental data on the origin of the neutrons not yet conclusive, need more shots; and (4) Applications -- (a) Fusion 2.5 and 14 MeV neutron source; (b) Pulsed subcritical neutron source with uranium blanket for {approx}10x neutron and {approx}1000x energy multiplication (Smirnov, Feoktistov and Klimov); and (c) Fusion-assisted keV x-ray plasma radiation source.

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TYPE Conference YEAR 2005
OSTI
Results 1–25 of 70
Results 1–25 of 70