First Observation of Magnetic Flux Rope Inside Electron Diffusion Region

Magnetic flux ropes (MFRs) play a crucial role during magnetic reconnection. They are believed to be primarily generated by tearing mode instabilities in the electron diffusion region (EDR). However, they have never been observed inside the EDR. Here, we present the first observation of an MFR inside an EDR. The bifurcated nonforce-free MFR, with a width of similar to 27.5 d(e) in the L direction and similar to 4.8 d(e) in the N direction, was moving away from the X-line. Inside the MFR, strong energy dissipation was detected. The MFR can modulate the electric field in the EDR. We reconstructed magnetic topology of the electron-scale MFR. Our study promotes understanding of MRFs' initial state and its role in electron-scale processes during magnetic reconnection.

Automated summary

This study presents the first observation of a magnetic flux rope (MFR) inside an electron diffusion region (EDR), confirming its crucial role in magnetic reconnection. By observing and analyzing the structure and energy dissipation of MFR, it helps to understand the modulation of the electric field in EDR by MFR.