Experimental investigations of ablation stream interaction dynamics in tungsten wire arrays: Interpenetration, magnetic field advection, and ion deflection

Journal Article · Sun May 15 00:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4948279· OSTI ID:22600248

Swadling, G. F.; Lebedev, S. V.; Hall, G. N.; Suzuki-Vidal, F.; Burdiak, G. C.; Pickworth, L.; De Grouchy, P.; Skidmore, J.; Khoory, E.; Suttle, L.; Bennett, M.; Hare, J. D.; Clayson, T.; Bland, S. N.; Smith, R. A.; Stuart, N. H.; Patankar, S.; Robinson, T. S. ^[1]; Harvey-Thompson, A. J. ^[2]; Rozmus, W. ^[3] ; others, and

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1. Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)
2. Sandia National Laboratories, PO Box 5800, Albuquerque, New Mexico 87185-1193 (United States)
3. Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1 (Canada)

Experiments have been carried out to investigate the collisional dynamics of ablation streams produced by cylindrical wire array z-pinches. A combination of laser interferometric imaging, Thomson scattering, and Faraday rotation imaging has been used to make a range of measurements of the temporal evolution of various plasma and flow parameters. This paper presents a summary of previously published data, drawing together a range of different measurements in order to give an overview of the key results. The paper focuses mainly on the results of experiments with tungsten wire arrays. Early interferometric imaging measurements are reviewed, then more recent Thomson scattering measurements are discussed; these measurements provided the first direct evidence of ablation stream interpenetration in a wire array experiment. Combining the data from these experiments gives a view of the temporal evolution of the tungsten stream collisional dynamics. In the final part of the paper, we present new experimental measurements made using an imaging Faraday rotation diagnostic. These experiments investigated the structure of magnetic fields near the array axis directly; the presence of a magnetic field has previously been inferred based on Thomson scattering measurements of ion deflection near the array axis. Although the Thomson and Faraday measurements are not in full quantitative agreement, the Faraday data do qualitatively supports the conjecture that the observed deflections are induced by a static toroidal magnetic field, which has been advected to the array axis by the ablation streams. It is likely that detailed modeling will be needed in order to fully understand the dynamics observed in the experiment.

• OSTI ID: 22600248
• Journal Information: Physics of Plasmas, Vol. 23, Issue 5; Other Information: (c) 2016 Author(s); 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
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABLATION
ADVECTION
COMPUTERIZED SIMULATION
CYLINDRICAL CONFIGURATION
DRAWING
FARADAY EFFECT
IMAGES
INTERACTIONS
IONS
LASERS
MAGNETIC FIELDS
PLASMA
STREAMS
THOMSON SCATTERING
TUNGSTEN
WIRES