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DOE OSTI · 2567561

Quadrupolar density structures in driven magnetic reconnection experiments with a guide field

Varnish, T. W. O. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:000000028078214X)·Chen, J. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000234328069)·Chowdhry, S. [Massachusetts Institute of Technology, Cambridge, MA (United States)]·Datta, R. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0000000196118449)·Dowhan, G. V. [University of Michigan, Ann Arbor, MI (United States); Naval Research Laboratory, Washington, DC (United States)] (ORCID:0000000179634361)·Horan, IV, L. S. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0000000309334026)·Jordan, N. M. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000195184284)·Neill, E. R. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0009000388540318)·Shah, A. P. [University of Michigan, Ann Arbor, MI (United States); University of California San Diego, La Jolla, CA (United States)] (ORCID:0000000254038077)·Shapovalov, R. [University of Michigan, Ann Arbor, MI (United States); Laboratory for Laser Energetics, Rochester, NY (United States)] (ORCID:0000000233598649)·Sporer, B. J. [University of Michigan, Ann Arbor, MI (United States); TAE Technologies, Inc., Foothill Ranch, CA (United States)] (ORCID:000000016290699X)·McBride, R. D. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000250229749)·Hare, J. D. [Massachusetts Institute of Technology, Cambridge, MA (United States); Cornell University, Ithaca, NY (United States)] (ORCID:000000027090828X)

Abstract

Magnetic reconnection is a ubiquitous process in plasma physics, driving rapid and energetic events such as coronal mass ejections. Reconnection between magnetic fields with arbitrary shear can be decomposed into an anti-parallel reconnecting component and a non-reconnecting guide-field component, which is parallel to the reconnecting electric field. This guide field modifies the structure of the reconnection layer and the reconnection rate. We present results from experiments on the MAIZE pulsed-power generator (500 kA peak current, 200 ns rise time), which use two exploding wire arrays, tilted in opposite directions, to embed a guide field in the plasma flows with a relative strength b≡B g /B rec =0, 0.4, or 1. The reconnection layers in these experiments have widths that are less than the ion skin depth, d i =c/ω pi , indicating the importance of the Hall term, which generates a distinctive quadrupolar magnetic field structure along the separatrices of the reconnection layer. Using laser imaging interferometry, we observe quadrupolar structures in the line-integrated electron density, consistent with the interaction of the embedded guide field with the quadrupolar Hall field. Our measurements extend over much larger length scales (40d i ) at higher β (∼1) than previous experiments, providing an insight into the global structure of the reconnection layer.

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Varnish, T. W. O. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:000000028078214X), Chen, J. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000234328069), Chowdhry, S. [Massachusetts Institute of Technology, Cambridge, MA (United States)], Datta, R. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0000000196118449), Dowhan, G. V. [University of Michigan, Ann Arbor, MI (United States); Naval Research Laboratory, Washington, DC (United States)] (ORCID:0000000179634361), Horan, IV, L. S. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0000000309334026), Jordan, N. M. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000195184284), Neill, E. R. [Massachusetts Institute of Technology, Cambridge, MA (United States)] (ORCID:0009000388540318), Shah, A. P. [University of Michigan, Ann Arbor, MI (United States); University of California San Diego, La Jolla, CA (United States)] (ORCID:0000000254038077), Shapovalov, R. [University of Michigan, Ann Arbor, MI (United States); Laboratory for Laser Energetics, Rochester, NY (United States)] (ORCID:0000000233598649), Sporer, B. J. [University of Michigan, Ann Arbor, MI (United States); TAE Technologies, Inc., Foothill Ranch, CA (United States)] (ORCID:000000016290699X), McBride, R. D. [University of Michigan, Ann Arbor, MI (United States)] (ORCID:0000000250229749), Hare, J. D. [Massachusetts Institute of Technology, Cambridge, MA (United States); Cornell University, Ithaca, NY (United States)] (ORCID:000000027090828X). 2025-02-26. Quadrupolar density structures in driven magnetic reconnection experiments with a guide field. https://doi.org/10.1063/5.0251581

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