Implosion dynamics and K-shell x-ray generation in large diameter stainless steel wire array Z pinches with various nesting configurations

Journal Article · Mon Dec 15 00:00:00 EST 2008 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3049909· OSTI ID:21259728

Jones, Brent; Coverdale, Christine A; Deeney, Christopher; Sinars, Daniel B; Waisman, Eduardo M; Cuneo, Michael E; Ampleford, David J ^[1]; LePell, P David; Cochrane, Kyle R ^[2]; Thornhill, J Ward; Apruzese, J P; Dasgupta, Arati ^[3]; Whitney, Kenneth G; Clark, Robert W ^[4]; Chittenden, Jeremy P ^[5]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)
2. Ktech Corporation, Albuquerque, New Mexico 87123 (United States)
3. Naval Research Laboratory, Washington, D.C. 20375 (United States)
4. Berkeley Scholars, Springfield, Virginia 22150 (United States)
5. Blackett Laboratory, Imperial College, London, SW7 2BW (United Kingdom)

Nested stainless steel wire array variations were investigated on the 20 MA Z machine [R. B. Spielman et al., Phys. Plasmas 5, 2105 (1998)]. In order to reach experimentally observed electron temperatures near 3.8 keV and excite the K shell, these {approx}6.7 keV photon energy x-ray sources must be of large initial diameter (45-80 mm) which poses a concern for magnetic Rayleigh-Taylor instability growth. We discuss the implosion dynamics in these large diameter wire arrays, including an analysis of the ablation phase indicating that the prefill material is snowplowed at large radius. Nested array configurations with various mass and radius ratios are compared for instability mitigation and K-shell scaling. Degradation of the K-shell x-ray power and yield was observed for shots that did not have simultaneous implosion of the outer and inner wire arrays. Shots that were designed per this constraint exhibited K-shell yield scaling consistent with the model of J. W. Thornhill et al. [IEEE Trans. Plasma Sci. 34, 2377 (2006)] which had been benchmarked to single array results. This lends confidence to K-shell yield predictions using this model for future shots on the refurbished Z machine. Initial results employing a triple nested wire array to stabilize the large diameter implosion are also reported.

• OSTI ID: 21259728
• Journal Information: Physics of Plasmas, Vol. 15, Issue 12; Other Information: DOI: 10.1063/1.3049909; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CONFIGURATION
ELECTRON TEMPERATURE
EXPLODING WIRES
IMPLOSIONS
K SHELL
LONGITUDINAL PINCH
PLASMA
RAYLEIGH-TAYLOR INSTABILITY
STAINLESS STEELS
X-RAY SOURCES