  A widely accepted scenario of magnetic reconnection in collisionless space
plasmas is the breakage of magnetic field lines in X-points. In laboratory,
reconnection is commonly studied in pinches, current channels embedded into
twisted magnetic fields. No model of magnetic reconnection in space plasmas
considers both null-points and pinches as peers. We have performed a
particle-in-cell simulation of magnetic reconnection in a three-dimensional
configuration where null-points are present initially, and Z-pinches are formed
during the simulation along the lines of spiral null-points. The non-spiral
null-points are more stable than spiral ones, and no substantial energy
dissipation is associated with them. On the contrary, turbulent magnetic
reconnection in the pinches causes the magnetic energy to decay at a rate of
~1.5% per ion gyro period. Dissipation in similar structures is a likely
scenario in space plasmas with large fraction of spiral null-points.

Space Physics;Earth and Planetary Astrophysics;Solar and Stellar Astrophysics;Plasma Physics