Page "Magnetic reconnection" Paragraph 31

On length scales shorter than the ion inertial length ( where is the ion plasma frequency ), ions decouple from electrons and the magnetic field becomes frozen into the electron fluid rather than the bulk plasma.

On these scales the Hall effect becomes important.

Two-fluid simulations show the formation of an X-point geometry rather than the double Y-point geometry characteristic of resistive reconnection.

The electrons are then accelerated to very high speeds by Whistler waves.

Because the ions can move through a wider " bottleneck " near the current layer and because the electrons are moving much faster in Hall MHD than in standard MHD, reconnection may proceed more quickly.

Two-fluid / collisionless reconnection is particularly important in the Earth's magnetosphere.