Radiation properties and implosion dynamics of planar and cylindrical wire arrays, asymmetric and symmetric, uniform and combined X-pinches on the UNR 1-MA zebra generator

• Published in: IEEE transactions on plasma science Vol. 34; no. 2; pp. 194 - 212
• Main Authors: Kantsyrev, V.L., Safronova, A.S., Fedin, D.A., Ivanov, V.V., Esaulov, A.A., Nalajala, V., Shrestha, I., Pokala, S., Williamson, K., Ouart, N.D., Yilmaz, M.F., Laca, P., Cowan, T.E., Rudakov, L.I., Jones, B., Coverdale, C.A., Deeney, C., LePell, P.D., Velikovich, A.L., Chuvatin, A.S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01-04-2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum; Arrays; Asymmetry; Conductivity; Copper; Couplings; Dynamics; Electron beams; Exact sciences and technology; Generators; Implosions; Lasers; Magnetic confinement and equilibrium; Nickel base alloys; Optical (ultraviolet, visible, infrared) measurements; Physics; Physics of gases, plasmas and electric discharges; Physics of plasmas and electric discharges; Plasma; Plasma diagnostic techniques and instrumentation; Plasma properties; Radiation; Spectroscopy; Spectrum analysis; Steel; Testing; Theta pinch; Wire; Wire arrays; X-pinches; X-ray and y-ray measurements; X-ray and γ-ray measurements; X-ray imaging; X-ray lasers; X-ray spectroscopy; X-rays; Z-pinch; Oscillation modes; Wire arrays; Implosions; Aluminium; X-ray spectroscopy; Experimental study; Molybdenum; X-pinches; X-ray imaging; ZEBRA reactor; Z-pinch; Plasma diagnostics; Tungsten; Laser spectroscopy; Longitudinal pinch; Spatial resolution
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2006.872173

In the following experiments, we studied implosions of different wire arrays and X-pinches produced on the 1-MA Zebra generator at the University of Nevada, Reno. Diagnostics included both spatially-resolved and time-gated X-ray imaging and spectroscopy, and laser probing. In particular, we compared planar wire arrays, to which little energy could be coupled via the conventional magnetic-to-kinetic conversion mechanism, to cylindrical wire arrays of comparable dimensions and mass. The planar wire arrays were shown to radiate much higher peak power and more energy in subkiloelectronvolt and kiloelectronvolt spectral ranges than cylindrical wire arrays. We tested the theoretical conjecture that enhanced resistivity due to the small-scale inhomogeneity of wire-array plasmas has a major effect on dynamics, energy coupling and radiation performance of wire-array Z-pinches. The study of Al, Alumel, and W cylindrical wire arrays shows a wide variety of characteristic behaviors in plasma implosions discussed hereinafter. Additional experimental results for symmetric and asymmetric, uniform stainless steel, Cu, Mo, combined Al/Mo, Mo/Al, Al/W, W/Al, and Mo/W X-pinches are also presented. New data for the total radiation yield are obtained. The planar structures of X-pinch plasma and the corresponding electron beam was observed for most of X-pinches. The generation of hot spots along original wires positions-cooler than those from the cross-wire region-and arc structures with hot spots between wires were found for X-pinches composed from Al, Cu, and W wires.