https://doi.org/10.1140/epjs/s11734-025-01686-w
Regular Article
Axion-electrodynamic revisions of Taylor’s results: force-free state with electric fields in fusion plasmas
1
School of Physics and Optoelectronic Engineering, Anhui University, 230601, Hefei, Anhui, China
2
School of Nuclear Science and Technology, University of Science and Technology of China, 230026, Hefei, Anhui, China
3
National Supercomputing Center in Zhengzhou, Zhengzhou University, 450001, Zhengzhou, Henan, China
4
Anhui Zhongke Yineng Technology Co. Ltd., 230031, Hefei, Anhui, China
5
Institute of Material Science and Information Technology, Anhui University, 230601, Hefei, Anhui, China
Received:
18
February
2025
Accepted:
12
May
2025
Published online:
27
May
2025
Force-free magnetic fields play a crucial role in astrophysical and fusion plasmas, particularly in reversed field pinch (RFP) experiments. The classical Woltjer–Taylor state describes a force-free configuration where the current is parallel to the magnetic field, but it does not account for electric fields, which are essential in fusion plasmas. This study extend Taylor’s model by incorporating electric fields using axion electrodynamics, where the current and charge density are determined by the axion field. Solving for electromagnetic fields in cylindrical geometry, we recover Taylor’s results in the limit of vanishing electric fields. For specific parameters, the solutions take the form of modified Bessel functions, revealing structures such as “current holes,” which have been observed in Tokamak experiments but not in RFP systems. These results offer new insights into the role of electric fields in force-free plasmas and their impact on fusion confinement dynamics.
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© The Author(s), under exclusive licence to EDP Sciences, Springer-Verlag GmbH Germany, part of Springer Nature 2025
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
