Fundamental understanding of magnetic reconnection via spiral CT scan

It is still poorly understood at present how magnetic reconnection—a universal process in space, laboratory, and astrophysical plasmas—is triggered and developed, because there was no efficient technique to analyze such a super-dynamic and three-dimensional process. Even with the launch of NASA's MMS mission, studies of this process were still based on in-situ measurements along spacecraft trajectories and qualitative comparison with a schematic, which is stationary, two-dimensional, and oversimplified. As a result, using such conventional methodologies, the fundamental physics andinherent nature of magnetic reconnection cannot be uncovered. Here we invent a three-dimensional CT imaging technique, analogous to that in the hospital, and apply it to a magnetic reconnection in space. With the help of such an advanced technique, we at least made three exciting discoveries: (1) magnetic reconnection is triggered by whistler waves and developed by Hall effects; (2) magnetic reconnection accelerates electrons and converts energy via parallel electric fields; (3) magnetic reconnection converts magnetic energy to particle energy in the inflow region but inversely converts particle energy to magnetic energy near the X point, with the net conversion being (B_inflow²-B_outflow²)/2m₀during the whole process. These discoveries have upended the conventional concept and completely unraveled the fundamental nature of magnetic reconnection.