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Current Sheet Dynamics of High Guide-Field Magnetic Reconnection

Yuka DOKE¹⁾, Yasushi ONO^1,2)

1)

Department of Electrical Engineering and Information Systems, Graduate School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan

2)

Department of Advanced Energy, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561, Japan

(Received 4 September 2024 / Accepted 27 September 2024 / Published 20 December 2024)

Abstract

We measured detailed current sheet dynamics of two merging high-guide field flux tubes using newly developed high-resolution magnetic field measurement by Printed-Circuit-Board (PCB) coils in TS-6 merging tokamak experiment. We found that the sheet ejection occurred twice, increasing their merging ratio, the toroidal current density J_t, the toroidal electric field E_t, and the effective resistivity η of current sheet. The possible explanation for this result is that the mass ejection from the current sheet drives the reconnection inflow, due to the mass conservation law. Especially, after the second sheet ejection, the effective resistivity increased significantly, probably because the sheet thickness compressed up to the ion Larmor radius.

Copyright (c) 2024 The Japan Society of Plasma Science and Nuclear Fusion Research

Keywords

magnetic reconnection, fast reconnection, current sheet, anomalous resistivity, plasma pile-up

DOI: 10.1585/pfr.19.1201032

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References

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