Magnetic Reconnection

What is magnetic reconnection?

Magnetic reconnection is a fundamental physical process occuring in a magnetized plasma, whereby magnetic field lines are effectively broken and reconnected, resulting in a change of magnetic topology, conversion of magnetic field energy into bulk kinetic energy and particle heating. Reconnection is responsible for many dynamic phenomena in the the laboratory, the Earth's magnetosphere, the Sun, and many astrophysical settings. Reconnection is illustrated in the animation at right, created by M. Shay, University of Maryland. Current out of the page is plotted in orange, while magnetic field lines are shown in black. Field lines drift in towards the center of the page and reconnect. After they reconnect, the magnetic field line tension flings the plasma to the left or right away from the x-line. Near the x-line a very large negative (colored black) current forms.

To view the animation, click the graphic above.

Recent Simulations

I have been investigating forced reconnection. This simulation uses a cosine profile for the initial B_x(y), and employs a vertical forcing function. The grid size is 512x512 with a physical system size of 102.4 x 102.4 collisionless ion skin depths. The forcing function, which is localized near the x-line, is a sum of tanh's in the y direction and is a gaussian in the x direction. I'll add a description of the shape and functional form of the forcing function soon. Again, the animation shows current in the z direction (out of the page).

To view the animation, click the graphic above.